Thermoplastic elastomer composition for powder molding, powder and molded article thereof

ABSTRACT

A thermoplastic elastomer composition for powder molding comprising 100 parts by weight of a polyolefin-based resin(A) and 10 to 1000 parts by weight of a specific hydrogenated vinyl aromatic compound-conjugated diene-based block copolymer(B), a powder of the thermoplastic elastomer composition, a method for powder molding the same, a molded article obtained by the method for powder molding, and a multi-layer molded article containing the molded article as one layer.

This is a divisional of Application No. 09/584,400 filed Jun. 1, 2000now U.S. Pat. No. 6,521,705; the disclosure of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thermoplastic elastomer compositionfor powder molding, powder, a powder molding method and a moldedarticle. More specifically, the present invention relates to athermoplastic elastomer composition for powder molding which comprises apolyolefin-based resin and a hydrogenated diene-based copolymer having aspecific structure as essential components, and which can provide amolded article that is not easily whitened on bending, and does notgenerate gloss when heated at temperatures from about 80° C. to lessthan the melting point of the polyolefin-based resin; a powder composedof said composition; a powder molding method using said powder; a moldedarticle obtained by powder-molding said powder; and a multi-layer moldedarticle using said molded article.

2. Description of the Related Arts

Conventionally, molded articles in the form of a sheet having on thesurface complicated uneven patterns such as leather grains, stitches andthe like are used as skin materials of automobile interior parts or thelike. As such molded articles, there have been proposed molded articlesobtained by powder molding of a powder which is produced by pulverizingan olefin-based thermoplastic elastomer, for replacing conventionalmolded articles of vinyl chloride-based resins (see, e.g., JP-A-05-1183and JP-A-05-5050). However, a molded article obtained by such a methodis harder and has a property that it is easily whitened on bending, ascompared with vinyl chloride-based resin molded articles, therefore,there was a tendency that the bent portion was whitened to causeappearance failure when the molded article was released from a moldafter production and when the molded article was molded into intendedform, and the like. Further, JP-A-07-82443 discloses a powder resincomposition composed of a polyolefin-based resin and a hydrogenatedstyrene-butadiene rubber having a styrene content of 20% by weight orless, and JP-A-03-72512 discloses a thermoplastic elastomer compositioncomposed of a non-polar resin such as polypropylene or the like, and ahydrogenated diene-based copolymer having a specific structure.

A molded article obtained by powder molding of these powder resincompositions had a problem that when used as an automobile interiormaterial, appearance failure occurs, since the molded article revealsgloss when heated at a temperatures from about 80° C. to less than themelting point of the polyolefin-based resin (it is known that when anautomobile is left outdoor in summer, temperature of the surface ofautomobile interior materials such as an instrument panel reaches up toabout 80 to 120° C.) though when the molded article is bent, the bentportion is not whitened.

Two-layer molded articles constituted of a skin layer composed of avinyl chloride-based resin and a foamed layer composed of apolyurethane-based resin are widely used for automobile interior partssuch as an instrument panel, console box, door trim and the like.Recently, there is an effort to unify a skin layer and a foamed layerinto a thermoplastic elastomer composition material from viewpoints ofrecycle and the like, however, there has not been known a two-layermolded article in which both of a skin layer and a foamed layer arecomposed of a thermoplastic elastomer composition, and which is notwhitened on bending, does not reveal gloss when heated at temperaturesfrom about 80° C. to less the melting point of the polyolefin-basedresin, and has excellent cushioning property.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a thermoplasticelastomer composition for powder molding which comprises apolyolefin-based resin and a hydrogenated diene-based copolymer having aspecific structure as essential components, and which can provide amolded article that is excellent in flexibility, is not easily whitenedon bending in the bent portion, and further, does not generate glosswhen heated at temperatures from about 80° C. to less than the meltingpoint of the polyolefin-based resin, a powder composed of saidcomposition and a powder molding method using said powder.

Another object of the present invention is to provide a molded articleobtained by powder-molding this powder and a two-layer or multi-layer(three or more layer) molded article using this molded article.

Still another object of the present invention is to provide a two-layeror multi-layer molded article having an excellent cushioning property inaddition to the above-descried properties, comprising theabove-mentioned molded article as a skin layer and a foamed layercomposed of a thermoplastic elastomer composition containing apolyolefin-based resin and a rubbery polymer having a specificstructure.

Other objects and advantages of the present invention will be apparentfrom descriptions below.

Namely, the present invention relates to a thermoplastic elastomercomposition for powder molding comprising 100 parts by weight of thefollowing component (A) and 10 to 1000 parts by weigh of the followingcomponent (B), wherein the complex dynamic viscosity η*(1) at 250° C. is1.5×10⁵ poise or less, and the Newtonian viscosity index n is 0.67 orless:

(A): a polyolefin-based resin,

(B): a hydrogenated diene-based copolymer satisfying all of thefollowing conditions {circle around (1)} to {circle around (7)},

{circle around (1)}: the hydrogenated diene-based copolymer contains thefollowing structural units (a) and (b):

(a): a vinyl aromatic compound polymer block,

(b): at least one block selected from the group consisting of following(b1), (b2) and (b3):

(b1): a block obtained by hydrogenation of a random copolymer blockcomposed of a vinyl aromatic compound and a conjugated diene,

(b2): a block obtained by hydrogenation of a tapered copolymer blockcomposed of a vinyl aromatic compound and a conjugated diene in whichthe amount of the vinyl aromatic compound increases gradually,

(b3): a block obtained by hydrogenation of a conjugated diene polymerblock,

{circle around (2)}: the total content(T: percentage) of vinyl aromaticcompound units contained in the hydrogenated diene-based copolymer isfrom 10 to 18% by weight,

{circle around (3)}: the ratio (S: percentage) of the content of thevinyl aromatic compound unit of (a) in {circle around (1)} to the totalcontent of vinyl aromatic compound units contained in the hydrogenateddiene-based copolymer is 3% or more,

{circle around (4)}: the ratio (V: percentage) of the number ofhydrogenated conjugated diene units having a side chain of two or morecarbon atoms to the total number of hydrogenated conjugated diene unitsin the hydrogenated diene-based copolymer is over 60%,

{circle around (5)}: (T) in {circle around (2)}, (S) in {circle around(3)} and (V) in {circle around (4)} in the hydrogenated diene-basedcopolymer satisfy the relation represented by the following expression(1):

V≦0.375×S+1.25×T+40  (1)

{circle around (6)}: 80% or more of double bonds derived from conjugateddiene units in the hydrogenated diene-based copolymer are hydrogenated,and

{circle around (7)}: the number average molecular weight of thehydrogenated diene-based copolymer is from 50000 to 400000.

Further, the present invention relates to a powder of theabove-mentioned thermoplastic elastomer composition for powder moldingand a powder molding method using said powder.

Furthermore, the present invention relates to a molded article obtainedby powder-molding the powder, and a two-layer or multi-layer moldedarticle containing said molded article and a method for producing thesame.

Still further, the present invention relates to a two-layer moldedarticle comprising (I) a layer of the above-mentioned thermoplasticelastomer composition for powder molding and (II) a layer describedbelow:

(II): a foamed layer composed of a thermoplastic elastomer compositioncontaining 100 parts by weight of the following component (G) and 10 to1000 parts by weight of the following component (H):

(G): a polyolefin-based resin,

(H): a rubbery polymer wherein in tan δ—temperature-dependence curveobtained by measuring solid viscoelasticity of a composition prepared bykneading with (G), a new single tan δ peak is given at a temperaturedifferent from both of the tan δ peak temperature of (G) and the tan δpeak temperature of (H), in a temperature range from −70 to 30° C.

Also, the present invention relates to a multi-layer molded article inwhich a thermoplastic core material is laminated on the side of thelayer (II) of the two-layer molded article, and a method for producingthe same.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be illustrated in detail below.

The component (A) in the present invention is a polyolefin-based resin,and is at least one selected from homopolymers or copolymers of olefinshaving a high crystallinity. Examples of the olefin include ethylene andα-olefins having 3 to 8 carbon atoms such as propylene, 1-butene,1-hexene, 1-octene and the like. Examples of (A) include polyethylene,polypropylene, poly(1-butene), copolymers of propylene with ethylene,and copolymers of propylene with another α-olefin (for example, 1-buteneor the like). When (A) is a propylene-ethylene copolymer resin or apropylene-1-butene copolymer resin, the thermoplastic elastomercomposition of the present invention is preferable because a moldedarticle having an excellent heat-resistance and flexibility can beobtained.

The crystallinity of the resin(A) is required to 50% or more, andpreferably 60% or more. Herein, the crystallinity means the ratio of thefusion heat of the resin(A) to the fusion heat of a crystallinepolyolefin homopolymer composed solely of an olefin unit of whichcontent by weight is the highest among olefins in the resin(A) used, andproduced by using the same catalyst system under the same conditions(temperature, pressure, use amount of catalyst, and the like). Thefusion heat is measured by a differential scanning calorimetry (DSC).

Further, there can also be used a copolymer obtained by copolymerizationof two or more monomers selected from ethylene and α-olefins having 3 to8 carbon atoms in two or more steps. For example, there can be used acopolymer obtained by homopolymerizing propylene in the first step, andcopolymerizing propylene with ethylene or an α-olefin other thanpropylene in the second step to obtain a copolymer. From the viewpointof the strength of a molded article obtained by a powder molding method,the melt flow rate (hereinafter, referred to as “MFR”) of (A) measuredaccording to JIS K-7210 at a temperature of 230° C. under a load of 2.16kg is usually from 20 to 500 g/10 min., preferably from 50 to 300 g/10min., particularly preferably from 100 to 300 g/10 min.

The component (B) in the present invention is a hydrogenated diene-basedcopolymer satisfying all of the above-mentioned conditions {circlearound (1)} to {circle around (7)}. Examples of the conjugated dieneused for producing (B) include conjugated dienes having 4 to 8 carbonatoms such as 1,3-butadiene, isoprene, 1,3-pentadiene,2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene and the like. Amongthem, 1,3-butadiene and isoprene are preferable in that they can beeasily utilized industrially, and a hydrogenated diene-based copolymerhaving excellent physical property is obtained.

The vinyl aromatic compound may be substituted at 1- or 2-position ofthe vinyl group by an alkyl group such as a methyl group or the like.Examples of the vinyl aromatic compound include vinyl aromatic compoundshaving 8 to 12 carbon atoms such as styrene, p-methylstyrene,α-methylstyrene, t-butylstyrene, divinylbenzene, vinylpydirine and thelike. Among them, styrene is preferably used from the industrialstandpoint.

(B) usually has a constitution represented by the general formula[(a)−(b)]_(n), [(a)−(b)]_(n)−(a) or [(b)−(a)]_(n)−(b) (wherein, n is aninteger of 1 or more, when repeating units (a) and (b) are present inplural number, a plurality of (a)s and (b)s may be the same ordifferent, respectively, and b is b1, b2 or b3. Among them, hydrogenateddiene-based copolymers represented by (a)−(b1)−(a), (a)−(b2)−(a) and(a)−(b3)−(a) are preferable since they are easily produced industrially.A hydrogenated compound of a styrene-butadiene·styrene-styrenecopolymer, a hydrogenated compound of a styrene-butadiene-styrenecopolymer, a hydrogenated compound of a styrene-isoprene·styrene-styrenecopolymer, and a hydrogenated compound of a styrene-butadiene-styrenecopolymer are preferable since they are easily produced industrially.Particularly, a hydrogenated compound of a styrene-butadiene-styrenecopolymer is preferable in that the resulted molded article hasexcellent strength and impact resistance at low temperature, and thestrength of the resulted molded article is scarcely influenced even ifthere is industrial delicate variation in the ratio (V: percentage) ofthe number of hydrogenated conjugated diene units having a side chain oftwo or more carbon atoms to the total number of hydrogenated conjugateddienes in a hydrogenated diene-based copolymer described below. Herein,“−” indicates the border line between blocks, and “·” indicates that twoor more compounds are used together in one block.

The total content of vinyl aromatic compound units in (B) is required tobe in a range from 10 to 18% by weight (condition {circle around (2)}),and preferably from 12 to 17% by weight. When the total content of vinylaromatic compound units is over 18% by weight, a molded article obtainedby molding the thermoplastic elastomer composition tends to become hard.Whereas, when the total content of vinyl aromatic compound units is lessthan 10% by weight, there is a problem that the resulted molded articlehas a stickiness. The total content of vinyl aromatic compound units isdetermined by measuring ¹H-NMR at a frequency of 90 MHz or more using asolution of (B) in carbon tetrachloride or the like.

The ratio (S: percentage) of the content of the vinyl aromatic compoundunit of the vinyl aromatic compound polymer block (a) to the totalcontent of vinyl aromatic compound units in (B) is required to 3% ormore, and preferably from 30 to 100%, further preferably from 50 to100%. When the ratio is less than 3%, there is a problem that theresulted molded article has a stickiness. This ratio is determined bymeasuring ¹H-NMR at a frequency of 90 MHz or more using a solution of(B) in carbon tetrachloride or the like.

The ratio (V: percentage) of the number of hydrogenated conjugated dieneunits having a side chain of two or more carbon atoms to the totalnumber of hydrogenated conjugated diene units in the conjugateddiene-based copolymer in (B) is required to be 60% or more (condition{circle around (4)}), and preferably from 60 to 85%, further preferablyfrom 65 to 80%. When the ratio is less than 60%, the resulted moldedarticle becomes hard. In the case of 60 to 85%, when the heat-resistanceof a molded article is evaluated, the change of the surface condition(gloss generation condition) can be strictly suppressed. This ratio canbe measured by Morero method using infrared analysis.

It is necessary that the total content (T: weight percentage) of vinylaromatic compound units, the ratio (S: percentage) of the content of thevinyl aromatic compound unit of the vinyl aromatic compound polymerblock (a) to the total content of vinyl aromatic compound units, and theratio (V: percentage) of the number of hydrogenated conjugated dieneunits having a side chain of two or more carbon atoms to the totalnumber of hydrogenated conjugated diene units in the conjugateddiene-based copolymer, in (B), satisfy the following formula (1)(condition {circle around (5)}):

V≦0.375×S+1.25×T+40  (1)

If the above-described expression (1) is not satisfied, there is aproblem that when the resulted molded article is heated at temperaturesfrom about 80° C. and less than the melting point of a polyolefin-basedresin, the molded article generates gloss.

It is necessary that 80% or more of double bonds of in conjugated dieneunits in (B) are hydrogenated (condition {circle around (6)}), and thishydrogenation ratio is preferably 90% or more, particularly preferably96% or more. When the hydrogenation ratio is less than 80%, there is aproblem that the light resistance of the resulted molded article becomesinferior.

It is necessary that the number-average molecular weight of (B) is from50000 to 400000 (condition {circle around (7)}) for obtaining a moldedarticle having excellent appearance and strength, and the number-averagemolecular weight is preferably from 100000 to 300000. When thenumber-average molecular weight is less than 50000, the resulted moldedarticle manifests generation of stickiness, and additionally, thermalresistance and light resistance become insufficient. When thenumber-average molecular weight is over 400000, the melting property ofthe thermoplastic elastomer composition of the present invention ispoor, and resultantly, a molded article having a good appearance andsufficient strength can not be obtained. The number-average molecularweight is measured by a GPC method.

It is preferable that MFR of (B) measured according to JIS K-7210 at atemperature of 230° C. under a load of 2.16 kg is from 1 to 200 g/10min., further from 5 to 100 g/10 min., since a molded article having agood appearance and sufficient strength can be obtained.

(B) used in the present invention may be modified with a functionalgroup, and alternatively, there may be used a functional group-modifiedproduct thereof having at least one functional group selected from acidanhydride group, carboxyl group, hydroxyl group, amino group, isocyanategroup and epoxy group. When these groups are used, there can be obtaineda merit of improvement of adhesive property when the resulted moldedarticle is adhered to a polyurethane foamed layer to produced atwo-layer molded article or multi-layer molded article, for example.

Such a hydrogenated diene-based copolymer can be produced by methodsdescribed in JP-A-3-72512, JP-A-5-271325, JP-A-5-217327, JP-A-6-287365and the like, for example.

The thermoplastic elastomer composition for powder molding of thepresent invention may also contain (C) an ethylene-α-olefin-basedcopolymer, in addition to the essential components (A) and (B). If (C)is contained, a thermoplastic elastomer composition for powder moldingwhich does not generate gloss when heated at temperatures from about 80°C. to less than the melting point of a polyolefin-based resin, andfurther, which has an excellent impact resistance at low temperature, isprovided, without lowering the powder molding property of athermoplastic elastomer powder, and without lowering the whiteningresistance of bent portion when a molded article obtained bypowder-molding the powder is bent.

The ethylene-α-olefin-based copolymer (C) is a copolymer of ethylene andα-olefin, a copolymer of ethylene, α-olefin and non-conjugated diene, orthe like, which has scarce crystallinity or a crystallinity of less than50%. Herein, the crystallinity means the ratio of the fusion heat of thecopolymer to the fusion heat of a polyethylene homopolymer produced byusing the same catalyst system under the same conditions (temperature,pressure, used amount of catalyst, and the like). The fusion heat ismeasured by a DSC method. Examples of the α-olefin include α-olefinshaving 3 to 10 carbon atoms such as propylene, 1-butene,3-methyl-1-butene and the like, and examples of the non-conjugated dieneinclude non-conjugated dienes having 5 to 15 carbon atoms such asdicyclopentadiene, 5-ethylidine-2-norbornene, 1,4-hexadiene,1,5-cyclooctadiene, 5-methylene-2-norbornene and the like. As theethylene-α-olefin based copolymer, there are exemplified aethylene-propylene copolymer, ethylene-1-butene copolymer,ethylene-1-hexene copolymer, ethylene-1-octene copolymer,ethylene-propylene-5-ethylidene-2-norbornene copolymer (hereinafter,referred to as “EPDM”) and the like. Such an ethylene-α-olefin basedcopolymer may be crosslinked.

The α-olefin unit content in (C) is preferably from 5 to 40% by weight,preferably from 10 to 35% by weight, and the ethylene unit content isusually from 60 to 95% by weight, preferably from 65 to 90% by weight.The α-olefin unit content and ethylene unit content can be measured by a¹³C-NMR method, infrared absorption analysis method or the like. TheMooney viscosity measured at 100° C. {ML₁₊₄(100° C.)} according to ASTMD-927-57T of this ethylene-α-olefin based copolymer is preferably from10 to 350, more preferably from 15 to 300, from the viewpoint of thestrength of a molded article obtained by powder-molding thethermoplastic elastomer composition for powder molding of the presentinvention.

When (C) is used, the amount of (C) is 250 parts by weight or less,preferably from 20 to 200 parts by weight based on 100 parts by weightof (A). When the amount of (C) is too large, stickiness may occur on themolded article obtained by the powder molding method.

Further, the thermoplastic elastomer composition for powder molding ofthe present invention may contain a styrene-based thermoplasticelastomer other than the above-mentioned (B) as a component (D), inaddition to the essential components (A) and (B). As the component (D),there are exemplified hydrogenated diene-based copolymers containing thesame structural units (a) and (b) as in (B), hydrogenated compounds ofvinyl aromatic compound-conjugated diene random copolymers, and thelike. As the hydrogenated diene-based copolymer containing the samestructural units (a) and (b) as in (B) which is an example (D), thereare listed hydrogenated diene-based copolymers which do not satisfy atleast one of the conditions {circle around (2)} to {circle around (7)}as specified in (B).

For example, when hydrogenated diene-based copolymers which does notsatisfy the condition {circle around (5)} and satisfy the conditions{circle around (1)} to {circle around (4)} and {circle around (6)} to{circle around (7)} are used (the following relation was satisfied:V>0.375×S+1.25×T+40), a thermoplastic elastomer composition for powdermolding having more excellent scratch resistance can be obtained.

When a hydrogenated diene-based copolymer which does not satisfy thecondition {circle around (4)} is used (a hydrogenated diene-basedcopolymer in which the ratio (V: percentage) of the number ofhydrogenated conjugated diene units having a side chain of two or morecarbon atoms to the total number of hydrogenated conjugated diene unitsin the hydrogenated diene-based copolymer is less than 60% is used), athermoplastic elastomer composition for powder molding having moreexcellent impact resistance at low temperature can be obtained.

When (D) is used, the amount of (D) is 250 parts by weight or less,preferably from 20 to 200 parts by weight based on 100 parts by weightof (A). When the amount of (D) is too large, there occurs, for example,a demerit that stickiness may occur on the resulted molded article.

The thermoplastic elastomer composition for powder molding of thepresent invention may contain, if necessary, polymer components (E)other than the above-mentioned components (A) to (D), such ashydrogenated products of conjugated diene polymers, rubbery polymerssuch as natural rubber, butyl rubber, chloroprene rubber,epichlorohydrin rubber, acrylic rubber and the like, ethylene-acrylicacid copolymer, ethylene-vinyl acetate copolymer and saponified productsthereof, ethylene-methyl methacrylate copolymer, ethylene-glycidylacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-vinylacetate copolymer and the like. Among them, hydrogenated products ofconjugated diene polymers are preferable.

As the hydrogenated product of a conjugated diene polymer rubber, thereare listed hydrogenated polybutadiene, hydrogenated polyisoprene, andthe like. The ratio (V: percentage) of the number of hydrogenatedconjugated diene units having a side chain of two or more carbon atomsto the total number of hydrogenated conjugated diene units in thehydrogenated diene-based copolymer is preferably over 60% from thestandpoint of the flexibility of a molded article obtained by powdermolding, and the hydrogenated compound of a conjugated diene polymer maybe constituted of two or more blocks having different (V)s. As thehydrogenated diene polymer, polymers described in JP-A-3-74409, CEBC6200manufactured by JSR Corporation, and the like are listed. When (E) iscontained in the thermoplastic elastomer composition of the presentinvention, the strength of the resulted molded article increasesparticularly when the thermoplastic elastomer composition contains (C).

When the hydrogenated product of the conjugated diene polymer is used,the amount thereof is 250 parts by weight or less, preferably from 20 to200 parts by weight based on 100 parts by weight of (A). When the amountof (C) is too large, stickiness may occur on the molded article obtainedby the powder molding method.

The thermoplastic elastomer composition for powder molding of thepresent invention may contain various additives, such as, for example,mineral oil-based softening agents, thermal stabilizers(e.g.phenol-based thermal stabilizer, sulfite-based thermal stabilizer,phenylalkane-based thermal stabilizer, phosphite-based thermalstabilizer, amino-based thermal stabilizer, amide-based thermalstabilizer), weathering stabilizers, antistatic agents, pigments,lubricants (e.g. metal soap, wax), antifungus agents, antimicrobialagents, fillers and the like.

When the thermoplastic elastomer composition for powder molding of thepresent invention contains a mineral-based softening agent, there can beobtained a thermoplastic elastomer composition powder excellent inmelting property and a powder-molded article excellent in flexibility.

When the thermoplastic elastomer composition for powder molding of thepresent invention contains a pigment, a molded article which is noteasily decolored by wiping with an organic solvent such as hexane,benzine, toluene or the like, can be obtained. As the pigment, there canbe used organic pigments such as azo pigments, phthalocyanine pigmentsand threne pigments, and dyeing lakes and the like; and inorganicpigments such as oxides such as titanium oxide and the like, chromicacid molybdic acid-based pigments, selenium sulfide compound, ferrocyancompound, carbon black and the like.

As the pigment, any of liquid compounds and powdery compounds can beused. When a pigment in the form of powder is used, the primary particlesize is preferably 300 nm or less from the standpoint of uniformcoloration. Further, when a pigment in the form of powder is used, thosesupported on carriers such as calcium carbonate, metal soap, magnesiumoxide or the like can also be used. In this case, the primary particlesize of the carrier is usually 10 μm or less, preferably from 1 to 5 μm.In this case, the weight ratio of the powder pigment to the carrier isusually from 20:80 to 80:20, preferably from 25:75 to 75:25.

The thermoplastic elastomer composition for powder molding of thepresent invention contains the above-mentioned (A) and (B) as essentialcomponents, and if necessary, at least one of (C) and (D). The amount of(B) is required to from 10 to 1000 parts by weight, preferably from 40to 200 parts by weight based on 100 parts by weight of (A). When theamount of (B) based on 100 parts by weight of (A) is less than 10 partsby weight, a molded article obtained by powder molding is inferior inflexibility, and when a molded article is bent, the bent portion tendsto be whitened, whereas, when over 1000 parts by weight, stickinessoccurs on a molded article obtained by powder molding, and thermalresistance and light resistance become insufficient.

Further, when powder obtained by mechanical pulverization describedbelow of the thermoplastic elastomer composition for powder molding ofthe present invention is powder-molded, the complex dynamic viscosityη*(1) at 250° C. of the composition is required to 1.5×10⁵ poise orless, preferably from 1×10² to 8×10⁴, further preferably from 3×10² to5×10⁴, particularly preferably from 3×10² to 1×10⁴. Herein, the complexdynamic viscosity η*(ω) is a value calculated according to the followingcalculation equation (2) at a temperature of 250° C. using the storagemodulus G′(ω) and the loss modulus G″((ω) at a vibration frequency of ω,and the complex dynamic viscosity η*(1) is a complex dynamic viscositywhen ω is 1 radian/second.

η*(ω)={[G′(ω)]² +[G″(ω)]²}^(1/2)/ω  (2)

When η*(1) is over the above-mentioned upper limit, there is a tendencythat the melt flowability of the thermoplastic elastomer composition ispoor, and it becomes difficult to produce a molded article by a moldingmethod such as a powder molding method in which the shear rate in themolding is usually as low as 1 second⁻¹ or less.

When the powder obtained by mechanical pulverization described below ofthe thermoplastic elastomer composition for powder molding of thepresent invention is powder-molded, the Newtonian viscosity index n isrequired to 0.67 or less, and preferably from 0.01 to 0.35, furtherpreferably from 0.03 to 0.25. Herein, the Newtonian viscosity index n isa value calculated according to the following calculation equation (3)using the above-mentioned complex dynamic viscosity η*(1) and a complexdynamic viscosity η*(100) measured at a temperature of 250° C. and avibration frequency of ω=100 radian/second.

n={log η*(1)−log η*(100)}/2  (3)

When the Newtonian viscosity index n is over the above-mentioned upperlimit, the mechanical strength of the resulted molded article lowers.

When powder obtained by a strand cut method, die face cut method orsolvent treating method described below from the thermoplastic elastomercomposition for powder molding of the present invention ispowder-molded, the complex dynamic viscosity η*(1) at 250° C. of thecomposition is preferably from 1×10² to 5×10⁴, further preferably from3×10² to 8×10³. In this case, Newtonian viscosity index n is required to0.28 or less, and preferably from 0.01 to 0.20, further preferably from0.03 to 0.15.

As the method for obtaining the thermoplastic elastomer composition ofthe present invention, there are listed the following methods, forexample. Namely, (A) and (B) and at least one of (C) and (D) compoundedif necessary may advantageously melt-kneaded. Further, the thermoplasticelastomer composition can also be produced by selecting all or severalkinds of the above-mentioned components, and kneading or dynamicallycrosslinking them, then, melt-kneading components which have not beenselected. For example, a thermoplastic elastomer composition of thepresent invention which contains (A), (B), (C) and (D) and in which (A)and/or (C) are crosslinked intramolecularly and/or intermolecularly, canusually be produced by dynamically crosslinking (A) and (C), then,further adding (B) and (D) and kneading them. Herein, in the kneading, asingle screw extruder, a twin screw extruder, kneader, rolls or the likecan be used. The compounding of the above-mentioned various additivesand various polymers can be conducted, for example, by using (A), (B),(C) or (D) into which these additives have been previously compounded,or compounding them in kneading or dynamic crosslinking theabove-mentioned components.

The dynamic crosslinking of the above-mentioned kneading mixture can beconducted by, for example, kneading the above-mentioned kneading mixtureand a crosslinking agent under heating. As the crosslinking agent, thereare usually used organic peroxides such as2,5-dimethyl-2,5-di(tert-butyl peroxyno)hexane, dicumyl peroxide and thelike. The crosslinking agent is used in an amount of usually 1 part byweight or less, preferably from 0.1 to 0.8 parts by weight, morepreferably from 0.2 to 0.6 parts by weight based on 100 parts of thetotal amount of (A) and (B) and at least one of (C) and (D) compoundedif necessary.

When an organic peroxide is used as the crosslinking agent, if dynamiccrosslinking is conducted in the presence of a crosslinking aid such asa bismaleimide compound or the like, a thermoplastic elastomercomposition for powder molding which gives a molded article having anexcellent heat resistance, can be obtained. In this case, the use amountof the organic peroxide is usually 0.8 parts by weight or less,preferably from 0.2 to 0.8 parts by weight, more preferably from 0.4 to0.6 parts by weight based on 100 parts of the total amount of (A), (B)and at least component of (C) and (D) optionally compounded, to becrosslinked.

The used amount of the crosslinking aid is usually 1.5 parts by weightor less, preferably from 0.2 to 1 part by weight, more preferably from0.4 to 0.8 parts by weight based on 100 parts of the total amount of(A), (B) and at least one of (C) and (D) compounded if necessary. Thecrosslinking aid is preferably compounded before addition of thecrosslinking agent, and usually added in pre-kneading theabove-mentioned components to be crosslinked.

The crosslinking of (A), (B) and at least one of (C) and (D) optionallycompounded can be conducted by kneading components to be crosslinkedamong them, a crosslinking agent and if necessary, a furthercrosslinking aid by using a single screw kneader or a twin screw kneaderwhile heating at a range from 150 to 250° C. Further, the crosslinkingcan also be conducted by a sulfur crosslinking or the like.

These additives and other polymer components may be previously containedin at least one of (A), (B) and (C) and (D) optionally compounded, ormay be compounded by kneading or the like in the above-describedkneading and dynamic crosslinking, or thereafter. When a mineral-basedsoftening agent is used, if an oil-extended ethylene-α-olefin-basedcopolymer prepared by previously adding the mineral-based softeningagent into (C) is used, the above-mentioned kneading and dynamiccrosslinking can be conducted easily.

For producing the thermoplastic elastomer composition for powder moldingof the present invention which satisfies the physical values representedby the above-described complex dynamic viscosity and Newtonian viscosityindex, the extent of the above-mentioned kneading and dynamiccrosslinking, kinds and use amounts of components constituting thethermoplastic elastomer composition, kinds and use amounts of acrosslinking agent and crosslinking aid in dynamic crosslinking, kindsand used amounts of additives and the like are selected appropriately.Among them, the shear rates of kneading and dynamic crosslinking havelarge influence on the above-mentioned physical values, and it ispreferable to conduct kneading and crosslinking at a shear rate of1×10³/second or more.

A powder of the thermoplastic elastomer composition for powder moldingof the present invention can be produced by a method in which athermoplastic elastomer composition obtained by the above-mentionedmethod is mechanically ground, or a strand cut method, die face cutmethod or solvent treating method.

As the method for pulverizing mechanically the thermoplastic elastomercomposition for powder molding of the present invention, there arelisted a freeze pulverizing method and normal temperature pulverizingmethod. The freeze pulverizing method is a method in which thethermoplastic elastomer composition for powder molding is cooled to theglass transition temperature thereof or lower, preferably −70° C. orlower, further preferably −90° C. or lower, and pulverization isconducted while keeping the frozen condition. Although the thermoplasticelastomer composition for powder molding can be ground at a temperaturehigher than the glass transition temperature thereof (normal temperaturepulverization), in this case, there is a tendency that the particle sizeof the resulted ground substance becomes non-uniform, and the powdermolding becomes difficult.

For conducting pulverization while keeping the cooled condition of thethermoplastic elastomer composition for powder molding, thepulverization is preferably conducted by a method showing excellentpulverization efficiency and generating small amount of heat, and forexample, a mechanical pulverization method using an impact type grindersuch as a ball mill or the like is used. As powder of a thermoplasticelastomer composition obtained in the above-method, it usually has asize passing through Tyler standard sieve 24 mesh (opening: 700 μm×700μm), preferably has a size passing through 28 mesh (opening: 590 μm×590μm), further preferably has a size passing through 32 mesh (opening: 500μm×500 μm), particularly preferably has a size passing through 42 mesh(opening: 355 μm×355 μm).

The powder of the thermoplastic elastomer composition for powder moldingof the present invention obtained by the above-mentioned pulverizationmethod is not uniform in particle shape, therefore, the powderflowability thereof can be improved by coating a fine powder (F) on thesurface thereof. As the fine powder (F), a fine powder having a primaryparticle size of 10 μm or less is used. Examples of the fine powder (F)include inorganic oxides, vinyl chloride resins for paste, metal saltsof fatty acids, calcium carbonate, powder pigments (providing when apigment is contained in a thermoplastic elastomer composition, it ispreferable that the color is the same as that of the pigment) and thelike. The primary particle size of the fine powder (F) is required to 10μm or less, preferably 5 μm or less, further preferably from 5 nm to 5μm. The primary particle size is a value obtained by photographing afine powder by transmission electron microscope (TEM), selecting about1000 particles at random and measuring the diameter of the particle, anddividing the sum of the diameter of these particles by the number of theparticles.

As the inorganic oxide, alumina, silica, alumina silica, calciumcarbonate and the like are listed. Alumina is a fine powder most ofwhich is constituted of a unit of the chemical formula Al₂O₃. Aluminahas various crystal forms, and any of crystal forms can be used. Theseare called α-alumina, β-alumina, γ-alumina and the like depending on thecrystal form. There are listed Alumina C (γ-alumina) manufactured byDegusa limited, AKP-G008 (α-alumina) manufactured by Sumitomo ChemicalCo., Ltd., and the like.

Silica is a fine powder most of which is constituted of a unit of thechemical formula SiO₂. Silica is produced by pulverizing naturaldiatomaceous earth, decomposition of sodium silicate, and the like.There are listed OX50 of Degusa limited, and the like. Alumina silica isan inorganic oxide containing the above-mentioned alumina and silica asmain components.

The inorganic oxide may be coated with dimethyl silicone oil or thelike, or may be surface-treated with a trimethylsilyl group or the like.

As the powder pigment, there can be used organic pigments such as azopigments, phthalocyanine pigments and threne pigments, and dyeing lakesand the like; and inorganic pigments such as oxide pigments such astitanium oxide and the like, chromic acid molybdic acid-based pigments,selenium sulfide compound, ferrocyan compound, carbon black and thelike.

Preferably, the fine powders (F) are used alone, or two or more of thosehaving a primary particle size of 10 μm or less are combined for use.For example, the inorganic oxide can be used alone, or the powderpigment and inorganic oxide can be combined for use. A powder having aprimary particle size of 300 nm or less and a powder having a primaryparticle size of 300 nm to 10 μm are combined and used as the finepowder (F), a powder of a thermoplastic elastomer composition for powdermolding having further excellent bulk specific gravity (packingproperty) and coagulation resistance can be obtained as compared withsingle use of the fine powder.

When a powder pigment is used, those supported on carriers such ascalcium carbonate, a metal soap, magnesium oxide and the like can alsobe used. In this case, the primary particle size of the carrier isusually 10 μm or less, preferably from 1 to 5 μm. In this case, theratio by weight of the powder pigment to the carrier is usually from20:80 to 80:20, preferably from 25:75 to 75:25.

The addition amount of the fine powder (F) is from 0.1 to 10 parts byweight, preferably from 0. 2 to 8 parts by weight based on 100 parts byweight of the powder of the thermoplastic elastomer composition forpowder molding obtained by the pulverization method. When the additionamount is less than 0.1 part by weight, good powder flowability andpowder molding property are not obtained. When over 10 parts by weight,there is a tendency that the resulted molded article has poor strengthsince heat fusion between powders of the thermoplastic elastomercomposition for powder molding decreases.

The method for compounding the fine powder (F) into the powder of thethermoplastic elastomer composition for powder molding is notparticularly restricted, providing the fine powder is uniformly adheredonto the powder of the thermoplastic elastomer composition. For example,a method in which blending is conducted using a blender equipped with ajacket, a high speed rotation mixer, or the like is used. Among them, amethod for preventing mutual adhesion of powders and for dispersinguniformly them by applying shearing force such as by a Henschel mixer,super mixer or the like is preferable. The compounding is usuallyconducted at room temperature.

The powder of the thermoplastic elastomer composition for powder moldingof the present invention can be produced also by the following methods.In this case, though a powder having an excellent powder flowability canbe obtained even if the above-mentioned fine powder (F) is not added,powder flowability can be further improved when the fine powder (F) isadded.

Solvent treating method: A thermoplastic elastomer composition is cooledto the glass transition temperature or less (usually −70° C. or less,preferably −90° C. or less), and ground.

Then, powder of the thermoplastic elastomer composition produced by theabove-mentioned freeze pulverization method is stirred in a solventwhich has poor compatibility with the thermoplastic elastomercomposition in the presence of a dispersing agent and an emulsifier at atemperature of not less than the melting temperature of thethermoplastic elastomer composition, preferably at a temperature higherthan the melting temperature by 30 to 50° C., then, cooled (see, forexample, JP-A No. 62-280226). In the solvent treating method, ethyleneglycol, polyethylene glycol, polypropylene glycol or the like, forexample, is used as the solvent, in an amount of usually from 300 to1000 parts by weight, preferably from 400 to 800 parts by weight basedon 100 parts by weight of the thermoplastic elastomer composition. Asthe dispersing agent, an ethylene-acrylic acid copolymer, silicic acidanhydride, titanium oxide or the like, for example, is used in an amountof usually from 5 to 20 parts by weight, preferably from 10 to 15 partsby weight based on 100 parts by weight of the thermoplastic elastomercomposition. As the emulsifier, polyoxyethylenesorbitan mono-laurate,polyethylene glycol mono-laurate, sorbitan tri-stearate or the like isused in an amount of usually from 3 to 15 parts by weight, preferablyfrom 5 to 10 parts by weight based on 100 parts by weight of thethermoplastic elastomer composition.

Strand cut method: A melted thermoplastic elastomer composition isextruded through a dice into air to obtain a strand, and this is cooledand cut (see, for example, JP-A No. 50-149747).

In the above-mentioned strand cut method, a die opening has a diameterof usually from 0.1 to 3 mm, preferably from 0.2 to 2 mm. Thedischarging amount of the thermoplastic elastomer composition per onedie opening of the die is usually from 0.1 to 5 kg/hr, preferably from0.5 to 3 kg/hr. The haul-off rate of a strand is usually from 1 to 100m/min., preferably from 5 to 50 m/min. The cooled strand is cut intousually 1.4 mm or less, preferably 0.3 to 1.2 mm.

Die face cut method: A melted thermoplastic elastomer composition is cutwhile being extruded through a die into water. In the die face cutmethod, a die opening has a diameter of usually from 0.1 to 3 mm,preferably from 0.2 to 2 mm. The discharged amount of the thermoplasticelastomer composition per one die opening of the die is usually from 0.1to 5 kg/hr, preferably from 0.5 to 3 kg/hr. The temperature of water isusually from 30 to 70° C., preferably from 40 to 60° C.

The powder of the thermoplastic elastomer composition for powder moldingcan be applied to various powder molding methods such as a powder slushmolding, flow impregnation, static coating, powder thermal spraying,powder rotation molding and the like. For example, the powder slushmolding is conducted as follows.

First step: A step in which a fluorine and/or silicon-based releaseagent is coated on the molding surface of a mold.

When the powder of the thermoplastic elastomer composition of thepresent invention is powder-molded and the molded article is removedfrom a mold in the sixth step, the resultant molded article may bebroken if the molded article is tried to be forcibly removed due tostrong adhesion with the inner surface of the mold. Therefore, thoughnot essential, it is preferable to coat the inner surface of the moldwith a spray of a silicone-based release agent, fluorine-based releaseagent or the like. As the silicone-based release agent, there areexemplified KF96SP (organic solvent-diluted product) manufactured byShin-Etsu Silicone K. K., and the like, and as the fluorine-basedrelease agent, there are exemplified Daifree GA-6010 (organicsolvent-diluted product) and ME-413 (water-diluted product) manufacturedby Daikin Industries, Ltd., and the like.

Second step: A step in which a powder of a thermoplastic elastomercomposition is fed on the molding surface of a mold heated to themelting temperature of the powder of a thermoplastic elastomercomposition, or higher.

Powder of the thermoplastic elastomer composition is fed on the moldingsurface of a mold heated to the melting temperature of the composition,or higher, usually from 160 to 32° C., preferably from 210 to 300° C. Inthis method, the mold is heated by a gas heating furnace method, heatmedium oil circulation method, a method of immersion into a heat mediumoil or heat flow sand, high frequency induction heating method or thelike. The heating time for heat fusion of a powder of a thermoplasticelastomer composition is appropriately selected depending on the sizeand thickness of the intended molded article and the like.

Third step: A step in which powder of the thermoplastic elastomercomposition is heated for a predetermined time on the molding surface inthe second step, and powder particles at least of which surfaces havebeen melted are adhered each other.

Forth step: A step in which after the given time has lapsed in the thirdstep, powders which have not been fused are recovered.

Fifth step: A step in which, if necessary, the mold carrying theremaining melted powder of a thermoplastic elastomer composition isfurther heated.

Sixth step: A step in which, following the fifth step, the mold iscooled, and a molded article formed thereon is removed from the mold.

The mold is cooled, and a molded article formed thereon is removed fromthe mold. Further, in producing the thermoplastic elastomer compositionfor powder molding, if the above-mentioned lubricant is internallyadded, there occurs such an effect that a load required for removing themolded article in the sixth step described before is reduced. In thiscase, the above-mentioned first step can also be omitted. The additionamount of a lubricant is usually 5 parts by weight or less, preferablyfrom 0.1 to 2 parts by weight based on 100 parts by weight of athermoplastic elastomer composition. When the addition amount of alubricant is over 5 parts by weight, there may occur problems that thestrength of the resulted molded article decreases, the mold surface isstained, and the like.

A foamed molded article can be produced by powder-molding the powder ofthe thermoplastic elastomer composition of the present inventioncontaining a foaming agent, and then foaming the powder-molded article.The foaming agent may be previously contained in the powder of thethermoplastic elastomer composition, or may be coated on the surface ofthe powder of the thermoplastic elastomer composition by a rotary mixersuch as the above-mentioned Henschel mixer or the like. The foamingagent can also be compounded simultaneously with the above-mentionedfine powder. As the foaming agent, a thermal decomposition type foamingagent is usually used. Examples of the thermal decomposition typefoaming agent include azo compounds such as azodicarboneamide,2,2′-azobisisobutyronitrile, diazodiaminobenzene and the like,sulfonylhydrazide compounds such as benzenesulfonylhydrazide,benzene-1,3-sulfonylhydrazide, p-toluenesulfonylhydrazide and the like,nitroso compounds such as N,N′-dinitrosopentamethylenetetramine,N,N′-dinitroso-N,N′-dimethylterephthalamide and the like, azidecompounds such as terephthalazide and the like, carbonates such assodium bicarbonate, ammonium bicarbonate, ammonium carbonate and thelike. Among other, azodicarboneamide is preferably used. The compoundingof a foaming agent is usually conducted at a temperature less than thedecomposition temperature of the foaming agent. The powder of thethermoplastic elastomer composition for powder molding of the presentinvention may also contain a foaming aid and a cell adjuster togetherwith a foaming agent.

A molded article obtained by molding the powder of the thermoplasticelastomer composition of the present invention is useful as a skinmaterial, and a two-layer molded article made by laminating a foamedlayer on one surface of the molded article may also be used as a skinmaterial. Such as two-layer molded article can be integrally produced bya power molding method (see, e.g. JP-A 5-473), and can also be producedby adhering a separately-produced foam onto the above-mentioned moldedarticle with a bonding agent or the like.

For producing a two-layer molded article by a powder molding, it isrecommendable that, for example, a mold which may have complicatedpatterns on the molding surface is heated to the melting temperature ofpowder of the thermoplastic elastomer composition, or higher, then, theabove-described powder of the thermoplastic elastomer composition is fedon the molding surface of the above-mentioned mold, powder particles areallowed to be thermally fused each other to obtain a melted product inthe form of a sheet on the molding surface, then, excess powder whichhas not been thermally fused is removed, then, a thermoplastic elastomerpowder containing a foaming agent (both of a powder in which a finepowder is compounded and a powder not containing the fine powder can beused) is fed on this melted sheet, and powder particles are allowed tobe thermally fused mutually to obtain a melted sheet on theabove-mentioned molding surface, then, excess powder which has not beenthermally fused is removed, then, further heated to cause foaming toform a foamed layer.

For example, production of a two-layer molded article by a powder slushmolding is conducted as follows. A layer(I) is produced in theabove-mentioned first to fifth steps, then, the following sixth orfurther steps are conducted to produce the two-layer molded article.

Sixth step: A step in which a powder of a thermoplastic elastomercomposition constituting a layer(II) is further fed on the moldingsurface of a mold.

The feeding time for thermally fusing the powder is appropriatelyselected depending on the size, thickness and expansion ratio of theintended molded article, and the like.

Seventh step: A step in which a powder of a thermoplastic elastomercomposition constituting the layer(II) on the molding surface in thesixth step is heated for a predetermined time, to cause mutual fusion ofpowder particles at least of which surfaces are melted.

Eighth step: A step in which, after the predetermined time in theseventh step has lapsed, powder which has not been fused is recovered.

Ninth step: A step in which, if necessary, the mold carrying the meltedpowder is further heated to cause foaming of the thermoplastic elastomercomposition constituting the layer(II).

Tenth step: A step in which, after the ninth step, the mold is cooled,and a two-layer molded article is removed from the mold.

Further, it is also possible to form a composite molded article composedof a non-foamed layer/formed layer/non-foamed layer by a powder molding.In this case, the non-foamed layers may be the same or different.

As the foaming agent, the same thermal decomposition type foaming agentsas described above are listed, and as the polymer components in athermoplastic elastomer composition containing such a foaming agent,there are exemplified vinyl chloride-based resins, polyolefins,olefin-based thermoplastic elastomers, and the like. Further, as thethermoplastic polymer composition containing a foaming agent, apolyethylene-based foaming composition used in JP-A 7-228720 can also beused.

Into a powder of this polyethylene-based foaming composition, the finepowder used in the present invention may also be compounded.

Further, a polyurethane foam can also be used as the foamed layer. Inthis case, since the adhesion between the thermoplastic elastomercomposition of the present invention and the polyurethane tends toinferior, the adhered surface of the molded article is pre-treated witha primer such as polyethylene chloride or the like to improve theadhesion.

The polyurethane foam is formed by fixing the above-mentioned moldedarticle and a core material described below to given positions at agiven interval, pouring a mixed solution of a polyol and apolyisocyanate into the clearance thereof, and allowing the mixture tofoam under positive pressure.

Further, as the material of the thermoplastic elastomer compositionfoamed layer constituting the layer(II), a thermoplastic elastomercomposition containing 100 parts by weight of the following (G) and 10to 1000 parts by weight of the following (H) is preferably used, sincethe composition give a two-layer molded article having excellentmoldability and cushioning property.

(G): Polyolefin-based resin

(H): Rubbery polymer wherein in tan δ-temperature-dependence curveobtained by measuring solid viscoelasticity of a composition prepared bykneading with (G), a new single tan δ peak is given at a temperaturedifferent from both of the tan δ peak temperature of (G) and the tan δpeak temperature of (H), in a temperature range from −70 to 30° C.

As the above-mentioned polyolefin-based resin (G), the above-mentionedpolyolefin-based resin (A) is used.

The above-mentioned rubbery polymer (H) is a rubbery polymer wherein intan δ-temperature-dependence curve obtained by measuring solidviscoelasticity of a composition prepared by kneading with (G), a newsingle tan δ peak is given at a temperature different from both of thetan δ peak temperature of (G) and the tan δ peak temperature of (H), ina temperature range from −70 to 30° C. This behavior does not depend onthe ratio by weight of the kneaded composition of (G) and (H).

As the component (H), conjugated diene-based rubbery polymers,hydrogenated conjugated diene-based rubbery polymers, and the like, arelisted.

The conjugated diene-based rubbery polymer means a conjugated dienepolymer rubber or conjugated diene-based copolymer rubber.

The conjugated diene polymer rubber is a polymer rubber which isobtained by polymerization or copolymerization of at least one ofconjugated dienes. Examples of the conjugated diene include conjugateddienes having 4 to 8 carbon atoms such as 1,3-butadiene,isoprene(2-methyl-1,3-butadiene), 1,3-pentadiene, 2,3-dimethylbutadieneand the like. Among these, 1,3-butadiene and isoprene are preferablefrom view points of industrially easy utilization and obtaining of aconjugated diene polymer rubber of excellent physical properties.

Examples of the conjugated diene polymer include polybutadiene,polyisoprene, polypentadiene, butadiene-isoprene copolymer and the like.

The conjugated diene-based copolymer rubber is a copolymer rubbercomposed of a conjugated diene selected from the conjugated dienes asdescribed above and a monomer other than the conjugated diene. Examplesof the monomer other than the conjugated diene include vinyl aromaticcompounds, vinylester compounds, ethylenically unsaturated carboxylicacid esters, vinylnitrile compounds and like, and among them, the vinylaromatic compounds are preferable since they are easily utilizedindustrially such as easy pelletization of the resulted copolymer.

In the vinyl aromatic compound, 1- or 2-position of the vinyl group maybe substituted with an alkyl group such as a methyl group and the like.Examples of the vinyl aromatic compound include vinyl aromatic compoundshaving 8 to 12 carbon atoms such as styrene, p-methylstyrene,α-methylstyrene, t-butylstyrene and the like. Among them, styrene ispreferable in that it can be utilized most easily industrially.

As the vinyl ester compound, vinyl acetate and the like are exemplified.

As the ethylenically unsaturated carboxylic acid ester, methylmethacrylate, ethyl methacrylate, methyl acrylate, butyl acrylate andthe like are exemplified.

As the vinylnitrile compound, acrylonitrile, methacrylonitrile and thelike are exemplified.

Examples of the conjugated diene-based copolymer rubber includeconjugated diene-vinyl aromatic compound copolymer rubbers such as abutadiene-styrene copolymer rubber, isoprene-styrene copolymer rubber,butadiene-p-methylstyrene copolymer rubber and the like, conjugateddiene-vinyl ester compound copolymer rubbers such as a butadiene-vinylacetate copolymer and the like, conjugated diene-ethylenicallyunsaturated carboxylic acid ester copolymer rubbers such as abutadiene-methacrylic acid copolymer rubber, butadiene-methyl acrylatecopolymer rubber and the like, conjugated diene-vinylnitrile compoundcopolymer rubbers such as a butadiene-acrylonitrile copolymer and thelike.

As the structure of such a conjugated diene-based copolymer rubber,there are listed random copolymers of a conjugated diene with a monomerother than the conjugated diene, block copolymers constituted of a blockof a conjugated diene polymer and a block of a polymer composed of amonomer other than the conjugated diene, block copolymers constituted ofa block of a conjugated diene polymer and a block of a copolymer of aconjugated diene and a monomer other than the conjugated diene, Amongthem, the block copolymer is preferably used from the standpoints ofcushioning property and sticking resistance of the layer(II), and thelike. The number of blocks constituting these block copolymers is 2 ormore, and 2 to 4 is preferable in that the copolymer can be easilyproduced industrially.

The hydrogenated conjugated diene-based rubber is a hydrogenatedconjugated diene polymer rubber or a hydrogenated conjugated diene-basedcopolymer rubber which is obtained by hydrogenation of theabove-described conjugated diene polymer rubber or conjugateddiene-based copolymer rubber, and as such a hydrogenated conjugateddiene-based rubber, hydrogenated products of the above-mentionedconjugated diene-based rubbers are listed, and preferably 80% or more ofdouble bonds in conjugated diene units are hydrogenated, and furtherpreferably, 90% or more are hydrogenated. When the hydrogenation ratiois less than 80%, the light resistance of the layer (II) tends todecrease.

In the conjugated diene-based copolymer rubber or hydrogenatedconjugated diene-based copolymer rubber, it is preferable that thecontent of monomer units other than conjugated dienes is usually 50% byweight or less, preferably 20% by weight or less, since a layer(II)having an excellent flexibility is obtained. When the content thereof isover 50% by weight, the flexibility of the layer(II) tends to decrease,and the cushioning property of a two-layer molder article tends todecrease.

When a hydrogenated conjugated diene-based rubber is used as thecomponent (H), the ratio of the number of hydrogenated conjugated dieneunits having a side chain of two or more carbon atoms to the totalnumber of hydrogenated conjugated diene units in the component (H) isrequired to 50% or more, preferably from 60 to 95%, further preferablyfrom 70 to 90% from the standpoint of the cushioning feeling of thelayer(II), though the ratio varies depending on the kind of theconjugated diene monomer used in the polymerization. This ratio can beobtained by Morero method using infrared spectrum analysis.

The melt flow rate (MFR) of (H) measured according to JIS K-7210 at atemperature of 230° C. and a load of 2.16 kgf is preferably from 0.1 to200 g/10 min., further preferably from 1 to 100 g/10 min., particularlypreferably from 3 to 80 g/10 min., since a layer(II) having a goodappearance and a sufficient cushioning property can be obtained.

(H) used in the present invention may be modified with a functionalgroup, and alternatively, there may also be used a functionalgroup-modified product having at least one functional group selectedfrom an acid anhydride group, carboxyl group, hydroxyl group, aminogroup, isocyanate group and epoxy group.

Such a rubbery polymer can be produced easily by the method describedin, for example, JP-A-2-36244, 3-72512, 7-118335, 56-38338, 61-60739 orthe like.

As (H), a propylene-1-butene-based copolymer rubber,propylene-α-olefin-ethylene-based copolymer rubber or the like can alsobe used.

The thermoplastic elastomer composition constituting the layer(II) ofthe present invention may also contain the following (J) and/or (K), inaddition to the essential components (G) and (H).

(J): Rubbery polymer wherein in tan δ-temperature-dependence curveobtained by measuring solid viscoelasticity of a composition prepared bykneading with (G), two tan δ peaks are given in a temperature range from−70 to 30° C.

(K): Ethylene-α-olefin-based copolymer

Though (J) is constituted of the same monomer as described for (H), itis a rubbery polymer having low compatibility with (G).

As (K), the above-mentioned ethylene-α-olefin-based compound (C) isused.

When (J) and/or (K) is contained, the low temperature impact-resistanceof the layer(II) can be improved without lowering the cushioningproperty of the layer(II).

When (J) and/or (K) is used, the amount of (J) and/or (K) is 250 partsby weight or less, preferably from 20 to 200 parts by weight based on100 parts by weight of (G). When the amount of (J) and/or (K) is toolarge, the durability of the resulted layer (II) may decrease.

The thermoplastic elastomer composition constituting the layer(II) inthe present invention may contain, if necessary, polymers such as anatural rubber, butyl rubber, chloroprene rubber, epichlorohydrinrubber, acrylic rubber and the like, and other polymer components suchas an ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymerand saponified products thereof, ethylene-methyl methacrylate copolymer,ethylene-glycidyl acrylate-vinyl acetate copolymer, ethylene-glycidylmethacrylate-vinyl acetate copolymer and the like, likewise as thethermoplastic elastomer composition constituting the layer (I) describedabove.

The molded article or two-layer molded article as described above ispreferably useful as a skin material to be laminated on a thermoplasticresin core material, and for example, the above-mentioned molded articlecan be used in a multi-layer molded article having on one surfacethereof a thermoplastic resin core material laminated, and the two-layermolded article can be used in a multi-layer molded article having on itsfoamed layer side a thermoplastic resin core material laminated.

As the thermoplastic resin in the thermoplastic resin core material, forexample, polyolefins such as polypropylene, polyethylene and the like,and thermoplastic resins such as ABS (acrylonitrile-butadiene-styrenecopolymer) resin and the like are used. Among them, polyolefins such aspolypropylene and the like are preferably used.

Such a multi-layer molded article can be produced easily by a method inwhich a thermoplastic resin melt is fed on one surface of the moldedarticle, and pressed or a method in which a thermoplastic resin melt isfed the foamed layer side of the two-layer molded article, and pressed.

The thermoplastic resin melt means a thermoplastic resin in the moltenstate by being heated to its melt temperature or higher. Thethermoplastic resin melt may be fed before the pressing, or simultaneouswith the pressing. Further, the pressing may be conducted using a moldor the like, or may also be conducted by feeding pressure of thethermoplastic resin melt. As such a molding method, there areexemplified an injection molding, low pressure injection molding, lowpressure compression molding and the like.

Specifically, for example, in case of using the above-mentioned moldedarticle as the skin material, the molded article is fed between a pairof opened molds, then, the molds are clamped after or while feeding athermoplastic resin melt between one surface of the molded article andone mold which is opposite to the surface, and in case of using theabove-mentioned two-layer molded article as the skin material, thetwo-layer molded article is fed between a pair of opened molds, then,the molds are clamped after or while feeding a thermoplastic resin meltbetween the foamed layer of the molded article and one mold which isopposite to the foamed layer. The opening and closing direction of themolds is not particularly restricted, and both of the vertical directionand horizontal direction may be permissible.

When the above-mentioned molded article or two-layer molded articleproduced by using a powder molding mold is used as a skin material, thismold for powder molding can be used as one of the molds in producing theabove-mentioned multi-layer molded article, while holding the moldedarticle or two-layer molded article on the molding surface of the moldfor powder molding. According to this method, the intended multi-layermolded article can be obtained with scarcely damaging patterns formed onthe surface, since the molded article or two-layer molded article towhich patterns on the mold have been transferred is fed between moldswithout being separated from the mold.

Though the thermoplastic resin melt may be fed after completion ofclamping of both molds, it is preferable to clamp both molds while orafter feeding the melt when the molds are not closed, since there islittle shift of the molded article or two-layer molded article which isa skin material, and a multi-layer molded article having also improveddegree of transfer of patterns. The method for feeding a thermoplasticresin melt is not particularly restricted, and for example, it can befed through a resin passage provided in one of molds facing the moldedarticle or two-layer molded article. Alternatively, it is allowable thata feeding nose of the resin melt is inserted between molds and the resinmelt is fed, then, the feeding nose is removed out of the system toclose the both molds.

As a pair of molds, a pair of male/female molds in which the outerperipheral surface of the one mold and the inner peripheral surface ofthe other mold are capable of sliding each other can also be used. Inthis case, by setting a clearance in sliding surfaces between the moldsto almost the same value as that of a thickness of the molded article ortwo-layer molded article, a multi-layer molded article having a marginalportion of the skin material around the article edges can be obtained,and a multi-layer molded article whose edges portions are covered withthe skin material layer can be obtained by folding back the marginalportion of the skin material onto the back side of the multi-layermolded article.

Furthermore, it is also possible to produce a multi-layer molded articleby putting a barrier layer on the layer (II)(foamed layer side) of thefore-mentioned two-layer molded article composed of the layers (I) and(II), feeding a thermoplastic resin melt on the barrier layer andpressing. The multi-layer molded article produced by this method showsbetter softness and touch-feeling because the barrier layer protects thedeterioration of cells in the foamed layer from heat and pressure.

Herein, the thickness of the barrier layer is particularly limited, butpreferably 0.5 to 3 mm, more preferably 0.7 to 2 mm. The barrier layeris usually used as a flat sheet, or a pre-formed one produced by vacuummolding, extrusion molding or the like. As a material of the barrier,there are listed olefin resins such as polyethylene, polypropylene,olefin-based thermoplastic elastomer, and the like.

Further, in the molded article, two-layer molded article and multi-layermolded article of the present invention, by coating the surface of thethermoplastic elastomer molded article side obtained by powder moldingof the powder of the thermoplastic elastomer composition of the presentinvention, with a paint, the scratch-resistance and friction-resistanceof the molded article can also be improved. As the paint, knownurethane-based paints, acrylic paints, as well as other paints can beused.

EXAMPLE

The present invention is illustrated by the following examples in detailbelow, but is not limit thereto.

Evaluations of a thermoplastic elastomer composition and a moldedarticle were conducted by the following methods.

[1] Complex dynamic viscosity η*(1) and Newtonian viscosity index n

The storage modulus G′ (ω) and the loss modulus G″ (ω) were measured byusing a Dynamic Analyzer (type RDR-7700) manufactured by Rheometrics ata vibration frequency (ω) of 1 radian/second or 100 radian/second, andthe complex dynamic viscosities η*(1) and η*(100) were calculatedaccording to the above-mentioned calculation equation (2). Themeasurement was conducted at parallel plates mode, an applied strain of5%, and a sample temperature of 250° C.

The Newtonian viscosity index n was calculated according to theabove-mentioned calculation equation (3) using η*(1) and η*(100).

[2] The total content (T) of vinyl aromatic compound units in thehydrogenated diene-based copolymer (B) was determined by a ¹H-NMRmeasuring method (frequency: 90 MHz) using a carbon tetrachloridesolution of (B).

[3] The ratio (V) of the number of hydrogenated conjugated diene unitshaving a side chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units in the hydrogenated diene-basedcopolymer (B)

It was measured by Morero method using infrared spectrum analysis.

[4] The ratio (S) of the content of a vinyl aromatic compound in thevinyl aromatic compound polymer block (a) to the total content of vinylaromatic compounds in a hydrogenated diene-based copolymer in (B)

It was determined by a ¹H-NMR measuring method (frequency: 90 MHz) usinga carbon tetrachloride solution of (B).

[5] Hydrogenation ratio of double bonds of conjugated diene units in ahydrogenated diene-based copolymer was determined by a ¹H-NMR measuringmethod (frequency: 90 MHz) using a carbon tetrachloride solution of (B).

[6] Number average molecular weight of a hydrogenated diene-basedcopolymer

It was determined by a gel permeation chromatography (GPC) method at 38°C. using a tetrahydrofuran solution of (B), as polystyrene-reducedvalue.

[7] Whitening on bending of a molded article obtained by powder moldingof a thermoplastic elastomer composition for powder molding

A molded sheet having a thickness of 1 mm obtained by a powder slushmolding described below was cut into 1 cm×5 cm, bent with a bending loadof 1 kg, and after 1 minute, the load was removed, and the whitening onbending was evaluated according to the following criteria.

1: Whitened portion was recognized.

2: Whitened portion was not recognized.

[8] Change of appearance when a molded article obtained by powdermolding of a thermoplastic elastomer composition is heated

A molded sheet having a thickness of 1 mm obtained by a powder slushmolding described below was cut into 15 cm×15 cm, placed for 100 hoursin a gear oven (manufactured by (TABAI K. K., Perfect Oven, type PH-200)of which temperature in the chamber was controlled to 110° C., glossvalues before and after the heating were measured by a digitaldeformation photometer (manufactured by Suga Shikenki K. K., typeUGV-5DI, reflection angle: 60°), and the appearance change was judgedbased on the difference in gloss values before and after the heatingaccording to the criteria described below:

1: Difference in gloss values was over 0.6.

2: Difference in gloss values was over 0.3 and not more than 0.6.

3: Difference in gloss values was 0.3 or less.

[9] Tensile property of a molded article obtained by powder molding of athermoplastic elastomer composition

From a molded sheet having a thickness of 1 mm obtained by a powderslush molding described below, a specimen was punched out using dumbbellof JIS No. 1, and subjected to a tensile test at a tension speed of 200mm/min., and the strength and elongation at break were measured.

[10] Solid viscoelasticity of a two-component composition composed of(G) and (H)

A viscoelasticity measuring apparatus, RHEOVIBRON (type DDV-II-EA)manufactured by Orientec Kogyo K. K. was used, and the tensile mode wasapplied. A sample of 2 cm×5 cm (distance between chucks: 3.5 cm)×0.1 mmthickness was made by a press molding, and the solid viscoelasticity wasmeasured by vibrating the sample at a temperature from −150° C. to 130°C., a temperature raising speed of 2° C./min., a vibration frequency of110 Hz, and a vibration amplitude of 16 μm, and the peak temperature andintensity of tan δ were measured.

[11] Change of appearance when a two-layer molded article is heated

A two-layer molded article obtained by a powder slush molding describedbelow was placed for 24 hours in a gear oven (manufactured by YamatoKagaku K. K., semi-explosion proof drier) of which temperature in thechamber was controlled to 110° C., change of gloss values before andafter the heating was judged according to the criteria described below.The gloss value was measured by a digital glossimeter (manufactured byMurakami Shikisai Gijutsu Kenkyusho, GM-26D, reflection angle: 60° C.).

◯: Difference in gloss values was less than 1.0

Δ: Difference in gloss values was 1.0 or more and less than 2.5

X: Difference in gloss values was 2.5 or more

[12] Change of appearance when a two-layer molded article is bent(shaping property)

A two-layer molded article obtained by a powder slush molding describedbelow was bent for 1 minute so that a load of 200 g/cm was applied,then, change of conditions of the bent portion was judged according tothe criteria described below:

◯: Bent portion was not whitened

X: Bent portion was significantly whitened

[13] Cushioning property of a two-layer molded article A hardness of thetwo-layer molded article obtained by a powder slush molding describedbelow was measured according to JIS K-6253, and this value was used asan index of the cushioning property.

Example 1

[Production of Powder of Thermoplastic Elastomer Composition]

[100 parts by weight of a propylene-ethylene copolymer resin[manufactured by Sumitomo Chemical Co., Ltd., ethylene unit content=5%by weight, MFR=228 g/10 min., crystallinity=70%], 100 parts by weight ofa hydrogenated product of a styrene-butadiene·styrene-styrene copolymer(corresponding to structure (a)−(b1)−(a) [total content of styreneunits=13% by weight, the content of a vinyl aromatic compound unit in(a) based on the total content of styrene units=69%, MFR=8 g/10 min.,the ratio of a hydrogenated conjugated diene unit having a side chain of2 or more carbon atoms based on the total amount of hydrogenatedconjugated diene units=70%, hydrogenation ratio=98%, number averagemolecular weight=170000], and carbon black as black pigment in an amountof 1 part by weight based on 100 parts by weight of thepropylene-ethylene copolymer resin were kneaded with a single screwkneader (manufactured by Tanabe Plastic Kikai K. K., VS40 mm, extruder)at a temperature of 170° C. to obtain a composition (η*(1)=1.2×10³poise, n=0.07), and this was cut using a cutting machine to obtainpellets.

The pellets were cooled to −120° C. with liquid nitrogen, then, groundwhile maintaining the cooled condition, to obtain a powder of thethermoplastic elastomer composition [passed through a Tyler standardsieve: 42 mesh (opening 355 μm×355 μm)].

[Production of Molded Article by Powder Slush Molding]

The resulted powder of a thermoplastic elastomer composition was fed onthe molding surface of a mold with grain patterns (30 cm square) heatedat 280° C., then, left for 15 seconds, the excess powder were droppedoff, and stored in an oven at 280° C. for 1 minute.

Then, a mold carrying a powder of a thermoplastic elastomer compositionmelted in the form of a sheet was cooled with water, and the sheet wasreleased from the mold, to obtain a molded article of the thermoplasticelastomer. The evaluation results of the molded article are shown inTable 2.

Examples 2 and 3

A molded article was obtained according to Example 1 except that ahydrogenated product of a styrene-butadiene·styrene-styrene copolymershown in Example 2 or 3 of Table 1 was used. The evaluation results areshown in Table 2.

Examples 4 and 5

A molded article was obtained according to Example 1 except that ahydrogenated product of a styrene-butadiene·styrene-styrene copolymershown in Example 4 or 5 of Table 3 was used. The evaluation results areshown in Table 4.

Examples 6 and 7

A molded article was obtained according to Example 1 except that ahydrogenated compound of a styrene-butadiene·styrene-styrene copolymershown in Example 6 or 7 of Table 5 was used. The evaluation results areshown in Table 6.

Examples 8 and 9

A molded article was obtained according to Example 1 except that ahydrogenated compound of a styrene-butadiene·styrene-styrene copolymershown in Example 8 or 9 of Table 7 was used. The evaluation results areshown in Table 8.

Comparative Examples 1 and 2

A molded article was obtained according to Example 1 except that ahydrogenated product of a styrene-butadiene·styrene-styrenecopolymer(Comparative Example 1) or a hydrogenated product of astyrene-butadiene-styrene copolymer(Comparative Example 2) shown inTable 9 was used. The evaluation results are shown in Tables 10.

Example 10

A molded article was obtained according to Example 1 except that 100parts by weight of a propylene-ethylene copolymer resin [manufactured bySumitomo Chemical Co., Ltd., ethylene unit content=5% by weight, MFR=228g/10 min., crystallinity=70%], 100 parts by weight of a hydrogenatedproduct of a styrene-butadiene·styrene-styrene copolymer [total contentof styrene units=16% by weight, the content of a vinyl aromatic compoundunit in (a) based on the total content of styrene units=85%, MFR=10 g/10min., the ratio of a hydrogenated conjugated diene unit having a sidechain of 2 or more carbon atoms based on the total amount ofhydrogenated conjugated diene units=75%, hydrogenation ratio=98%, numberaverage molecular weight=13000], 50 parts by weight anethylene-α-olefin-based rubber [manufactured by Sumitomo Chemical Co.,Ltd., Esprene V0141, propylene unit content=27% by weight, MFR=1 g/10min.] and black carbon black were kneaded by using a twin screw kneaderat a temperature of 180° C. to obtain a composition [η*(1)=2.0×10³poise, n=0.10]. The evaluation results thereof are shown in Table 12.

TABLE 1 (b) Hydrogenated diene-based copolymer Example 1 2 3 Structureof hydrogenated diene-based (a)-(b1)-(a) copolymer The total content ofstyrene units (% by 13 16 14 weight) The ratio (S:%) of the content ofthe vinyl 69 85 81 aromatic compound unit in (A) to the total content ofvinyl aromatic compound units MFR (g/10 min.)  8 10 12 The ratio (V:%)of the number of hydrogenated 70 75 72 conjugated diene units having aside chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units Relation expression (1) is satisfiedor not * ◯ ◯ ◯ (right side value) (82) (92) (88) V ≦ 0.375 × S + 1.25 ×T + 40 (1) Hydrogenation ratio (%) of double bonds 98 98 98 ofconjugated diene units Number average molecular weight of 17 13 13hydrogenated diene-based copolymer (X10000) * ◯: relation expression (1)is satisfied X: relation expression (1) is not satisfied

(hereinafter, the same)

TABLE 2 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 1 2 3 η*(1) (poise) 1.2 × 10³ 2.0 × 10³ 7× 10² n 0.07 0.10 0.04 Bending whitening property of 2 2 2 moldedarticle Change of appearance when molded 3 3 3 article is heatedStrength at break (kg/cm²) 99 95 120 Elongation at break (%) 420 500 580

TABLE 3 (b) Hydrogenated diene-based copolymer Example 4 5 Structure ofhydrogenated diene-based (a)-(b1)-(a) copolymer The total content ofstyrene units (% by 10 11 weight) The ratio (S:%) of the content of the72 59 vinyl aromatic compound unit in (A) to the total content of vinylaromatic compound units MFR (g/10 min.) 15 10 The ratio (V:%) of thenumber of 70 69 hydrogenated conjugated diene units having a side chainof two or more carbon atoms to the total number of hydrogenatedconjugated diene units Relation formula (1) is satisfied or not ◯ ◯(right side value) (80) (76) Hydrogenation ratio (%) of double bonds 9898 of conjugated diene units Number average molecular weight of 16 18hydrogenated diene-based copolymer (X10000)

TABLE 4 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 4 5 η^(‡)(1) (poise) 9 × 10² 1.0 × 10³ n0.04 0.04 Bending whitening property of 2 2 molded article Change ofappearance when molded 3 3 article is heated Strength at break (kg/cm²)81 94 Elongation at break (%) 350 450

TABLE 5 (b) Hydrogenated diene-based copolymer Example 6 7 Structure ofhydrogenated diene-based (a)-(b1)-(a) copolymer The total content ofstyrene units (% by 15 12 weight) The ratio (S:%) of the content of the54 81 vinyl aromatic compound unit in (A) to the total content of vinylaromatic compound units MFR (g/10 min.) 15  9 The ratio (V:%) of thenumber of 78 76 hydrogenated conjugated diene units having a side chainof two or more carbon atoms to the total number of hydrogenatedconjugated diene units Relation formula (1) is satisfied or not ◯ ◯(right side value) (79) (85) Hydrogenation ratio (%) of double bonds 9898 of conjugated diene units Number-average molecular weight of 16 14hydrogenated diene-based copolymer (X10000)

TABLE 6 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 6 7 η*(1) (poise) 8 × 10² 1.0 × 10³ n0.04 0.06 Bending whitening property of 2 2 molded article Change ofappearance when molded 2 3 article is heated Strength at break (kg/cm²)155 174 Elongation at break (%) 720 700

TABLE 7 (b) Hydrogenated diene-based copolymer Example 8 9 Structure ofhydrogenated diene-based (a)-(b1)-(a) copolymer The total content ofstyrene units (% 14 13 by weight) The ratio (S:%) of the content of the53 81 vinyl aromatic compound unit in (A) to the total content of vinylaromatic compound units MFR (g/10 min.) 12 10 The ratio (V:%) of thenumber of 65 63 hydrogenated conjugated diene units having a side chainof two or more carbon atoms to the total number of hydrogenatedconjugated diene units Relation formula (1) is satisfied or ◯ ◯ not(right side value) (77) (87) Hydrogenation ratio (%) of double bonds 9898 of conjugated diene units Number average molecular weight of 15 13hydrogenated diene-based copolymer (X10000)

TABLE 8 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 8 9 η*(1) (poise) 1.1 × 10³ 1.1 × 10³ n0.05 0.04 Bending whitening property of 2 2 molded article Change ofappearance when molded 3 3 article is heated Strength at break (kg/cm²)81 133 Elongation at break (%) 380 490

TABLE 9 Hydrogenated diene-based copolymer Comparative Example 1 2Structure of hydrogenated diene-based (a)-(b1)- (a)-(b3)- copolymer (a)(a) The total content of styrene units (% by  9 20 weight) The ratio(S:%) of the content of the 48 100  vinyl aromatic compound unit in (A)to the total content of vinyl aromatic compound units MFR (g/10 min.)  930 The ratio (V:%) of the number of 80 42 hydrogenated conjugated dieneunits having a side chain of two or more carbon atoms to the totalnumber of hydrogenated conjugated diene units Relation formula (1) issatisfied or not X ◯ (right side value) (69) (103)  Hydrogenation ratio(%) of double bonds 98 98 of conjugated diene units Number-averagemolecular weight of 20 10 hydrogenated diene-based copolymer (X10000)

TABLE 10 Physical properties of thermoplastic elastomer composition andmolded article thereof Comparative Example 1 2 η*(1) (poise) 1.7 × 10³ 8× 10² n 0.03 0.07 Bending whitening property of 2 1 molded articleChange of appearance when molded 1 2 article is heated Strength at break(kg/cm²) 108 70 Elongation at break (%) 610 240

TABLE 11 (b) Hydrogenated diene-based copolymer Example 10 Structure ofhydrogenated diene-based (a)-(b1)-(a) copolymer The total content ofstyrene units (% by 16 weight) The ratio (S:%) of the content of the 85vinyl aromatic compound unit in (A) to the total content of vinylaromatic compound units MFR (g/10 min.) 10 The ratio (V:%) of the numberof 75 hydrogenated conjugated diene units having a side chain of two ormore carbon atoms to the total number of hydrogenated conjugated dieneunits Relation formula (1) is satisfied or not ◯ (right side value) (92)Hydrogenation ratio (%) of double bonds 98 of conjugated diene unitsNumber-average molecular weight of 13 hydrogenated diene-based copolymer(X10000)

TABLE 12 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 10 η*(1) (poise) 2.0 × 10³ n 0.10 Bendingwhitening property of 2 molded article Change of appearance when molded3 article is heated Strength at break (kg/cm²) 70 Elongation at break(%) 550

Examples 11 to 14

A molded article was obtained according to Example 1 except that ahydrogenated products of a styrene-butadiene-styrene copolymers(corresponding to structure (a)−(b3)−(a)) shown in Table 13 were usedinstead of the hydrogenated compound of thestyrene-butadiene·styrene-styrene copolymer in Example 1. The evaluationresults are shown in Table 14.

TABLE 13 (b) Hydrogenated diene-based copolymer Example 11 12 13 14Structure of hydrogenated diene-based (a)-(b3)-(a) copolymer The totalcontent of styrene units (% by 15 15 15 15 weight) The ratio (S:%) ofthe content of the 100  100  100  100  vinyl aromatic compound unit in(A) to the total content of vinyl aromatic compound units MFR (g/10min.) 30 30 30 30 The ratio (V:%) of the number of 76 78 80 81hydrogenated conjugated diene units having a side chain of two or morecarbon atoms to the total number of hydrogenated conjugated diene unitsRelation formula (1) is satisfied or not ◯ ◯ ◯ ◯ (right side value) (96)(96) (96) (96) Hydrogenation ratio (%) of double bonds 98 98 98 98 ofconjugated diene units Number-average molecular weight of 13 13 13 13hydrogenated diene-based copolymer (X10000)

TABLE 14 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 11 12 13 14 η*(1) (poise) 1.1 × 10³ 1.0 ×10³ 1.0 × 10³ 1.0 × 10³ n 0.06 0.04 0.04 0.03 Bending whitening 2 2 2 2property of molded article Change of appearance 3 3 3 3 when moldedarticle is heated Strength at break 103 120 136 142 (kg/cm²) Elongationat break 680 690 770 770 (%)

Example 15

A molded article was obtained according to Example 1 except that 100parts by weight of a propylene-ethylene copolymer resin [manufactured bySumitomo Chemical Co., Ltd., ethylene unit content=5% by weight, MFR=228g/10 min., crystallinity=70%], 100 parts by weight of a hydrogenatedproduct of a styrene-butadiene-styrene copolymer (corresponding tostructure (a)-(b3)−(a)) shown in Table 15, 50 parts by weight anethylene-propylene copolymer rubber [manufactured by Sumitomo ChemicalCo., Ltd., Esprene V0141, propylene unit content=27% by weight, MFR=0.7g/10 min.] and 2.5 parts by weight of carbon black as a black pigmentwere used. The evaluation results thereof are shown in Table 16.

Example 16

A molded article was obtained according to Example 1 except that 100parts by weight of a propylene-ethylene copolymer resin (manufactured bySumitomo Chemical Co., Ltd., ethylene unit content=5% by weight, MFR=228g/10 min., crystallinity=70%), 108 parts by weight of a hydrogenatedproduct of a styrene-butadiene-styrene copolymer (corresponding tostructure (a)−(b3)−(a)) shown in Table 15, 38 parts by weight anethylene-propylene copolymer rubber (manufactured by Sumitomo ChemicalCo., Ltd., Esprene V0141, propylene unit content=27% by weight, MFR=0.7g/10 min.), a hydrogenated product of polybutadiene (manufactured by JSRCorp., CEBC6200P, MFR=2.5 g/10 min., hydrogenation ratio=98%] and 2.5parts by weight of carbon black as a black pigment were used. Theevaluation results thereof are shown in Table 16.

TABLE 15 (b) Hydrogenated diene-based copolymer Example 15 16 Structureof hydrogenated diene-based (a)-(b3)-(a) copolymer The total content ofstyrene units (% by 15 15 weight) The ratio (S:%) of the content of the100  100  vinyl aromatic compound unit in (A) to the total content ofvinyl aromatic compound units MFR (g/10 min.) 30 30 The ratio (V:%) ofthe number of 80 80 hydrogenated conjugated diene units having a sidechain of two or more carbon atoms to the total number of hydrogenatedconjugated diene units Relation formula (1) is satisfied or not ◯ ◯(right side value) (96) (96) Hydrogenation ratio (%) of double bonds 9898 of conjugated diene units Number-average molecular weight of 13 13hydrogenated diene-based copolymer (X10000)

TABLE 16 Physical properties of thermoplastic elastomer composition andmolded article thereof Example 15 16 η*(1) (poise) 1.3 × 10³ 1.3 × 10³ n0.05 0.04 Bending whitening property of 2 2 molded article Change ofappearance when molded 3 3 article is heated Strength at break (kg/cm²)85 94 Elongation at break (%) 680 690

Reference Example 1

(Production of layer(I) producing powder)

100 parts by weight of a propylene-ethylene copolymer resin[manufactured by Sumitomo Chemical Co., Ltd., ethylene unit content=5%by weight, MFR=220 g/10 min., crystallinity=70%], 100 parts by weight ofa hydrogenated product of a styrene-butadiene·styrene-styrene copolymer[corresponding to structure (a)−(b1)−(a), total content of styreneunits=16% by weight, the content of a vinyl aromatic compound unit in(a) based on the total content of styrene units=85%, MFR=10 g/10 min.,the ratio of a hydrogenated conjugated diene unit having a side chain of2 or more carbon atoms based on the total amount of hydrogenatedconjugated diene units=75%, hydrogenation ratio=98%, number averagemolecular weight=130000], 50 parts by weight an ethylene-propylenecopolymer rubber (manufactured by Sumitomo Chemical Co., Ltd., EspreneV0141, propylene unit content=27% by weight), and 1 part by weight ofcarbon black as a black pigment were kneaded by using a single screwkneader (manufactured by Tanabe Plastic Kikai K. K., VS40 mm, extruder)at a temperature of 170° C. to obtain a composition, and this was cutusing a cutting machine to obtain pellets [η*(1)=2.5×10³ poise, n=0.12].

The pellets were cooled to −120° C. with liquid nitrogen, then, groundwhile maintaining cooled condition, to obtain a powder of athermoplastic elastomer composition for producing the layer(I) [passedthrough a Tyler standard sieve: 42 mesh (opening 355 μm×355 μm)].

Reference Example 2

(Measurement of temperature and strength of tan δ peak of composition ofpolyolefin-based resin (G) and rubbery polymer (H))

As the component (H), a hydrogenated product of a butadiene-styrenecopolymer [styrene unit content=10% by weight, hydrogenation ratio 99%,the ratio of a hydrogenated conjugated diene unit having a side chain of2 or more carbon atoms based on the total amount of hydrogenatedconjugated diene units=80%, number average molecular weight=160000, peaktemperature of tan δ peak=−17° C., intensity=1.5] was used. As thepolyolefin-based resin (G), a propylene-ethylene random copolymer resin(peak temperature of tan δ peak=−7° C., intensity=0.12, ethylene unitcontent=5% by weight, MFR=228 g/10 min.) was used.

These were kneaded by using a LABOPLASTOMILL (manufactured by Toyo SeikiK. K., type 30C150) under conditions of 180° C. and 50 rpm for 10minutes at a ratio shown in Table 17 to obtain a composition (chargedamount to the LABOPLASTOMILL was 84 g), and the peak temperature andstrength of tan δ peak of the resulted composition were measured bysolid viscoelasticity measurement. The resulted composition gave a newsingle tan δ peak at a temperature different from both of the tan δ peaktemperature of (G) and the tan δ peak temperature of (H), in atemperature range from −70 to 30° C. The peak temperature and strengthof tan δ peak of these compositions are shown in Table 17.

TABLE 17 Temperature and strength of tan δ peak of composition of (G)and (H) Composition: parts by weight (G) 100 75 50 25 0 (H) 0 25 50 75100 Tan δ peak Temperature 7 −1 −7 −11 −17 Intensity 0.12 0.20 0.39 0.731.5

(Production of layer(II) producing powder]

100 parts by weight of a propylene-ethylene copolymer resin(manufactured by Sumitomo Chemical Co., Ltd., ethylene unit content=5%by weight, MFR=220 g/10 min., crystallinity=70%), 100 parts by weight ofthe above-described hydrogenated compound of the butadiene-styrenecopolymer (H), 50 parts by weight an ethylene-propylene copolymer rubber(manufactured by Sumitomo Chemical Co., Ltd., Esprene V0141, propyleneunit content=27% by weight), and 1 part by weight of carbon black as ablack pigment were kneaded by using a single screw kneader (manufacturedby Tanabe Plastic Kikai K. K., VS40 mm, extruder) at a temperature of170° C. to obtain a composition, and this was cut using a cuttingmachine to obtain pellets (η*(1)=2.7×10³ poise, n=0.07).

The pellets were cooled to −120° C. with liquid nitrogen, then, groundwhile maintaining cooled condition [passed through a Tyler standardsieve: 42 mesh (opening 355 μm×355 μm)].

Into 100 parts by weight of this ground compound was mixed 3 parts byweight of a powdery foaming agent (manufactured by Sankyo Kasei K. K.,azodicarboneamide (CAP-500, decomposition temperature=150° C.)) by usinga Super Mixer (manufactured by Kawata Seisakusho K. K., 5L Super MixerSVM-5) at 23° C. and 150 rpm for 5 minutes, to obtain a thermoplasticelastomer composition containing the foaming agent for producing thelayer(II).

Reference Example 3

(Production of layer(I) producing powder]

100 parts by weight of an oil-extended EPDM(ethylene-propylene-5-ethylidene-2-norbornen copolymer rubber: propyleneunit content=28% by weight, iodine value=12) (wherein, 50% by weight ofa mineral oil-based softening agent (Diana Process Oil PW-380,manufactured by Idemitsu Kosan Co., Ltd.) is contained), 100 parts byweight of a propylene-ethylene copolymer resin (ethylene unit content=5%by weight, MFR=90 g/10 min.), and 0.4 parts by weight of a crosslinkingaid (Sumifine BM, bismaleimide, manufactured by Sumitomo Chemical Co.,Ltd.) were kneaded for 10 minutes by using a Banbury mixer, then, theresulted composition was pelletized using an extruder to obtain a masterbatch. Then, to 100 parts by weight of this master batch was added 0.1part by weight of an organic peroxide (manufactured by Sanken Kako K.K., Sunperox APO, 2,5-dimethyl-2,5-di(t-butylperoxino)hexane, and themixture was dynamically crosslinked at 220° C. using a twin screwkneader (manufactured by The Japan Steel Works, Ltd., TEX-44) to obtaina composition (η*(1)=5.2×10³ poise, n=0.31), this was cut using acutting machine to obtain pellets.

The pellets were cooled to −120° C. with liquid nitrogen, then, groundwhile maintaining cooled condition, to obtain a powder of athermoplastic elastomer composition for producing the layer(I) (passedthrough a Tyler standard sieve: 42 mesh (opening 355 μm×355 μm)).

Example 17

The powder obtained in Reference Example 1 was fed on the moldingsurface of a mold with grain patterns (30 cm square) heated at 280° C.,then, 8 seconds after initiation of the feeding, unadhered excess powderwas dropped off from the mold. Then, 20 seconds after the dropping off,the powder obtained in Reference Example 2 was fed to the mold on whichthe powder obtained in Reference Example 1 was in the adhered state. 20seconds after initiation of the feeding, excess powder was dropped off.

Then, the product was stored in an oven at 280° C. for 1 minute, themold was cooled with water (cooling by shower from the surface of themold), and a two-layer molded article was released from the mold. Theevaluation results of this two-layer molded article are shown in Table18.

Comparative Example 3

A two-layer molded article was obtained according to Example 17 exceptthat a hydrogenated product of a styrene-butadiene·styrene-styrenecopolymer [corresponding to (a)−(b1)−(a), total content of styreneunits=10% by weight, the content of a vinyl aromatic compound unit in(a) based on the total content of styrene units=48%, MFR=10 g/10 min.,the ratio of a hydrogenated conjugated diene unit having a side chain of2 or more carbon atoms based on the total amount of hydrogenatedconjugated diene units=80%, hydrogenation ratio=98%, number-averagemolecular weight=130000] was used instead of the hydrogenated product ofthe styrene-butadiene styrene-styrene copolymer described in ReferenceExample 1 used in Example 17. The evaluation results thereof are shownin Table 18.

Comparative Example 4

A two-layer molded article was obtained according to Example 17 exceptthat a hydrogenated product of a butadiene-styrene copolymer [totalcontent of styrene units=16% by weight, the ratio of a hydrogenatedconjugated diene unit having a side chain of 2 or more carbon atomsbased on the total amount of hydrogenated conjugated diene units=75%,hydrogenation ratio=98%, number average molecular weight=160000.However, a composition obtained by kneading with the above-describedpropylene-ethylene copolymer resin did not give a new single tan δ peakat a temperature different from both of the tan δ peak temperature of(G) and the tan δ peak temperature of (H), in a temperature range from−70 to 30° C., and gave the same peak to each said temperature.] wasused instead of the hydrogenated product of the butadiene-styrenecopolymer described in Reference Example 2 in Example 17. The evaluationresults thereof are shown in Table 18.

Comparative Example 5

A two-layer molded article was obtained according to Example 17 exceptthat the powder described in Reference Example 3 was used instead of thepowder described in Reference Example 1 used in Example 17. Theevaluation results thereof are shown in Table 18.

TABLE 18 Example Comparative Example 17 3 4 5 Thickness of two-layermolded article (mm) layer(I) 0.8 0.8 0.8 0.8 layer(II) 2.7 2.7 2.7 2.7Change of appearance when ◯ X ◯ ◯ two-layer molded article is heatedChange of appearance when ◯ ◯ ◯ X two-layer molded article is bent(shaping property) Cushioning property of two- 58 58 62 66 layer moldedarticle (JIS-A)

As described above, according to the present invention, a thermoplasticelastomer composition for powder molding which comprises apolyolefin-based resin and a hydrogenated diene-based copolymer having aspecific structure as essential components, and which can provide amolded article that is excellent in flexibility, is not easily whitenedon bending in the bent portion, and further, does not reveal gloss whenheated at temperatures from about 80° C. to less than the melting pointof the polyolefin-based resin; a powder prepared from the composition; apowder molding using the powder; and a molded article obtained by apowder molding the powder can be provided.

What is claimed is:
 1. A two-layer molded article obtained by laminatingon one surface of a molded article a foamed layer, wherein said moldedarticle is obtained by powder molding a powder of a thermoplasticelastomer composition obtained by mechanically pulverizing athermoplastic elastomer composition comprising 100 parts by weight ofthe following component (A) and 10 to 1000 parts by weight of thefollowing component (B), wherein the composition has a complex dynamicviscosity η*(1) at 250° C. of 1.5×10⁵ poise or less and a Newtonianviscosity index n of 0.67 or less: (A): a polyolefin-based resin, and(B): a hydrogenated diene-based copolymer satisfying all of thefollowing conditions {circle around (1)} to {circle around (7)}, {circlearound (1)}: the hydrogenated diene-based copolymer comprises thefollowing structural units (a) and (b): (a): a vinyl aromatic compoundpolymer block, (b): at least one kind of block selected from thefollowing (b1), (b2) and (b3): (b1): a block obtained by hydrogenationof a random copolymer block composed of a vinyl aromatic compound and aconjugated diene, (b2): a block obtained by hydrogenation of a block inthe form of taper composed of a vinyl aromatic compound and a conjugateddiene in which the amount of the vinyl aromatic compound increasesgradually, (b3): a block obtained by hydrogenation of a conjugated dienepolymer block, {circle around (2)}: the total content (T: percentage) ofvinyl aromatic compound units contained in the hydrogenated diene-basedcopolymer from 10 to 18% by weight, {circle around (3)}: the ratio (S:percentage) of the content of the vinyl aromatic compound unit of (a) in{circle around (1)} to the total content of vinyl aromatic compoundunits contained in the hydrogenated diene-based copolymer is 3% or more,{circle around (4)}: the ratio (V: percentage) of the number ofhydrogenated conjugated diene units having a side chain of two or morecarbon atoms to the total number of hydrogenated conjugated diene unitsin the hydrogenated diene-based copolymer is over 60%, {circle around(5)}: (T) in {circle around (2)}, (S) in {circle around (3)} and (V) in{circle around (4)} in the hydrogenated diene-based copolymer satisfythe relation represented by the following formula (1):V≦0.375×S+1.25×T+40  (1) {circle around (6)}: 80% or more of doublebonds in conjugated diene units in the hydrogenated diene-basedcopolymer are hydrogenated, and {circle around (7)}: the number-averagemolecular weight of the hydrogenated diene-based copolymer is from 50000to 400000, and said foamed layer is prepared from a thermoplasticelastomer composition containing 100 parts by weight of the followingcomponent (G) and 10 to 1000 parts by weight of the following component(H): (G): a polyolefin-based resin, (H): a rubbery polymer, wherein, intan δ-temperature-dependent curve obtained by measuring solidviscoelasticity of a composition prepared by kneading with (G), a newsingle tan δ peak is given at a temperature different from both of thetan δ peak temperature of (G) and the tan δ peak temperature of (H), ina temperature range from −70 to 30° C.
 2. A multi-layer molded articleobtained by laminating a thermoplastic core material on the foamed layerside of the two-layer molded article of claim
 1. 3. A method forproducing a multi-layer molded article, which comprises feeding athermoplastic resin melt on the foamed layer side of the two-layermolded article of claim
 1. 4. A method for producing a multi-layermolded article, which comprises putting a barrier layer on the foamedlayer side of the two-layer molded article of claim 1, feeding athermoplastic resin melt on the barrier layer and pressing.
 5. Atwo-layer molded article obtained by laminating on one surface of amolded article a foamed layer, wherein said molded article is obtainedby powder-molding a powder of a thermoplastic elastomer compositionproduced by a strand cut method, die face cut method or solvent treatingmethod, the thermoplastic elastomer composition comprising 100 parts byweight of the following component (A) and 10 to 1000 parts by weight ofthe following component (B), wherein the composition has a complexdynamic viscosity η*(1) at 250° C. of 1.5×10⁵ poise or less and aNewtonian viscosity index n of 0.67 or less: (A): a polyolefin-basedresin, and (B): a hydrogenated diene-based copolymer satisfying all ofthe following conditions {circle around (1)} to {circle around (7)},{circle around (1)}: the hydrogenated diene-based copolymer comprisesthe following structural units (a) and (b): (a): a vinyl aromaticcompound polymer block, (b): at least one kind of block selected fromthe following (b1), (b2) and (b3): (b1): a block obtained byhydrogenation of a random copolymer block composed of a vinyl aromaticcompound and a conjugated diene, (b2): a block obtained by hydrogenationof a block in the form of taper composed of a vinyl aromatic compoundand a conjugated diene in which the amount of the vinyl aromaticcompound increases gradually, (b3); a block obtained by hydrogenation ofa conjugated diene polymer block, {circle around (2)}: the total content(T: percentage) of vinyl aromatic compound units contained in thehydrogenated diene-based copolymer from 10 to 18% by weight, {circlearound (3)}: the ratio (S: percentage) of the content of the vinylaromatic compound unit of (a) in {circle around (1)} to the totalcontent of vinyl aromatic compound units contained in the hydrogenateddiene-based copolymer is 3% or more, {circle around (4)}: the ratio (V:percentage) of the number of hydrogenated conjugated diene units havinga side chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units in the hydrogenated diene-basedcopolymer is over 60%, {circle around (5)}: (T) in {circle around (2)},(S) in {circle around (3)} and (V) in {circle around (4)} in thehydrogenated diene-based copolymer satisfy the relation represented bythe following formula (1): V≦0.375×S+1.25×T+40  (1) {circle around (6)}:80% or more of double bonds in conjugated diene units in thehydrogenated diene-based copolymer are hydrogenated, and {circle around(7)}: the number-average molecular weight of the hydrogenateddiene-based copolymer is from 50000 to 400000, and said foamed layer isprepared from a thermoplastic elastomer composition containing 100 partsby weight of the following component (G) and 10 to 1000 parts by weightof the following component (H); (G): a polyolefin-based resin, (H): arubber-like polymer wherein in tan δ-temperature-dependent curveobtained by measuring solid viscoelasticity of a composition prepared bykneading with (G), a novel single tan δ peak is given at a temperaturedifferent from both of the tan δ peak temperature of (G) and the tan δpeak temperature of (H), in a temperature range from −70 to 30° C.
 6. Amulti-layer molded article obtained by laminating a thermoplastic corematerial on the foamed layer side of the two-layer molded article ofclaim
 5. 7. A method for producing a multi-layer molded article, whichcomprises feeding a thermoplastic resin melt on the foamed layer side ofthe two-layer molded article of claim
 5. 8. A method for producing amulti-layer molded article, which comprises putting a barrier layer onthe foamed layer side of the two-layer molded article of claim 5,feeding a thermoplastic resin melt on the barrier layer and pressing. 9.A multi-layer molded article obtained by laminating a thermoplasticresin core material on one surface of a molded article obtained bypowder molding a powder of a thermoplastic elastomer compositionobtained by mechanically pulverizing a thermoplastic elastomercomposition comprising 100 parts by weight of the following component(A) and 10 to 1000 parts by weight of the following component (B),wherein the composition has a complex dynamic viscosity η*(1) at 250° C.of 1.5×10⁵ poise or less and a Newtonian viscosity index n of 0.67 orless: (A): a polyolefin-based resin, and (B): a hydrogenated diene-basedcopolymer satisfying all of the following conditions {circle around (1)}to {circle around (7)}, {circle around (1)}: the hydrogenateddiene-based copolymer comprises the following structural units (a) and(b): (a): a vinyl aromatic compound polymer block, (b): at least onekind of block selected from the following (b1), (b2) and (b3): (b1): ablock obtained by hydrogenation of a random copolymer block composed ofa vinyl aromatic compound and a conjugated diene, (b2): a block obtainedby hydrogenation of a block in the form of taper composed of a vinylaromatic compound and a conjugated diene in which the amount of thevinyl aromatic compound increases gradually, (b3): a block obtained byhydrogenation of a conjugated diene polymer block, {circle around (2)}:the total content (T: percentage) of vinyl aromatic compound unitscontained in the hydrogenated diene-based copolymer from 10 to 18% byweight, {circle around (3)}: the ratio (S: percentage) of the content ofthe vinyl aromatic compound unit of (a) in {circle around (1)} to thetotal content of vinyl aromatic compound units contained in thehydrogenated diene-based copolymer is 3% or more, {circle around (4)}:the ratio (V: percentage) of the number of hydrogenated conjugated dieneunits having a side chain of two or more carbon atoms to the totalnumber of hydrogenated conjugated diene units in the hydrogenateddiene-based copolymer is over 60%, {circle around (5)}: (T) in {circlearound (2)}, (S) in {circle around (3)} and (V) in {circle around (4)}in the hydrogenated diene-based copolymer satisfy the relationrepresented by the following formula (1): V≦0.375×S+1.25×T+40  (1){circle around (6)}: 80% or more of double bonds in conjugated dieneunits in the hydrogenated diene-based copolymer are hydrogenated, and{circle around (7)}: the number-average molecular weight of thehydrogenated diene-based copolymer is from 50000 to
 400000. 10. Amulti-layer molded article obtained by laminating a thermoplastic resincore material on one surface of a molded article obtained bypowder-molding a powder of a thermoplastic elastomer compositionproduced by a strand cut method, die face cut method or a solventtreating method, the thermoplastic elastomer composition comprising 100parts by weight of the following component (A) and 10 to 1000 parts byweight of the following component (B), wherein the composition has acomplex dynamic viscosity η*(1) at 250° C. of 1.5×10⁵ poise or less anda Newtonian viscosity index n of 0.67 or less: (A): a polyolefin-basedresin, and (B): a hydrogenated diene-based copolymer satisfying all ofthe following conditions {circle around (1)} to {circle around (7)},{circle around (1)}: the hydrogenated diene-based copolymer comprisesthe following structural units (a) and (b): (a): a vinyl aromaticcompound polymer block, (b): at least one kind of block selected fromthe following (b1), (b2) and (b3): (b1): a block obtained byhydrogenation of a random copolymer block composed of a vinyl aromaticcompound and a conjugated diene, (b2): a block obtained by hydrogenationof a block in the form of taper composed of a vinyl aromatic compoundand a conjugated diene in which the amount of the vinyl aromaticcompound increases gradually, (b3): a block obtained by hydrogenation ofa conjugated diene polymer block, {circle around (2)}: the total content(T: percentage) of vinyl aromatic compound units contained in thehydrogenated diene-based copolymer from 10 to 18% by weight, {circlearound (3)}: the ratio (S: percentage) of the content of the vinylaromatic compound unit of (a) in {circle around (1)} to the totalcontent of vinyl aromatic compound units contained in the hydrogenateddiene-based copolymer is 3% or more, {circle around (4)}: the ratio (V:percentage) of the number of hydrogenated conjugated diene units havinga side chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units in the hydrogenated diene-basedcopolymer is over 60%, {circle around (5)}: (T) in {circle around (2)},(S) in {circle around (3)} and (V) in {circle around (4)} in thehydrogenated diene-based copolymer satisfy the relation represented bythe following formula (1): V≦0.375×S+1.25×T+40  (1) {circle around (6)}:80% or more of double bonds in conjugated diene units in thehydrogenated diene-based copolymer are hydrogenated, and {circle around(7)}: the number-average molecular weight of the hydrogenateddiene-based copolymer is from 50000 to
 400000. 11. A method forproducing a multi-layer molded article, which comprises feeding athermoplastic resin melt on one surface of a molded article aridpressing, wherein said molded article is obtained by powder molding apowder of a thermoplastic elastomer composition obtained by mechanicallypulverizing a thermoplastic elastomer composition comprising 100 partsby weight of the following component (A) and 10 to 1000 parts by weightof the following component (B), wherein the composition has a complexdynamic viscosity η*(1) at 250° C. of 1.5×10⁵ poise or less and aNewtonian viscosity index n of 0.67 or less: (A): a polyolefin-basedresin, and (B): a hydrogenated diene-based copolymer satisfying all ofthe following conditions {circle around (1)} to {circle around (7)},{circle around (1)}: the hydrogenated diene-based copolymer comprisesthe following structural units (a) and (b): (a): a vinyl aromaticcompound polymer block, (b): at least one kind of block selected fromthe following (b1), (b2) and (b3): (b1): a block obtained byhydrogenation of a random copolymer block composed of a vinyl aromaticcompound and a conjugated diene, (b2): a block obtained by hydrogenationof a block in the form of taper composed of a vinyl aromatic compoundand a conjugated diene in which the amount of the vinyl aromaticcompound increases gradually, (b3): a block obtained by hydrogenation ofa conjugated diene polymer block, {circle around (2)}: the total content(T: percentage) of vinyl aromatic compound units contained in thehydrogenated diene-based copolymer from 10 to 18% by weight, {circlearound (3)}: the ratio (S: percentage) of the content of the vinylaromatic compound unit of (a) in {circle around (1)} to the totalcontent of vinyl aromatic compound units contained in the hydrogenateddiene-based copolymer is 3% or more, {circle around (4)}: the ratio (V:percentage) of the number of hydrogenated conjugated diene units havinga side chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units in the hydrogenated diene-basedcopolymer is over 60%, {circle around (5)}: (T) in {circle around (2)},(S) in {circle around (3)} and (V) in {circle around (4)} in thehydrogenated diene-based copolymer satisfy the relation represented bythe following formula (1): V≦0.375×S+1.25×T+40  (1) {circle around (6)}:80% or more of double bonds in conjugated diene units in thehydrogenated diene-based copolymer are hydrogenated, and {circle around(7)}: the number-average molecular weight of the hydrogenateddiene-based copolymer is from 50000 to
 400000. 12. A method forproducing a multi-layer molded article, which comprises feeding athermoplastic resin inch on one surface of a molded article andpressing, wherein said molded article is obtained by powder molding apowder of a thermoplastic elastomer composition for powder moldingproduced by a strand cut method, die face cut method or solvent treatingmethod, the thermoplastic elastomer composition comprising 100 parts byweight of the following component (A) and 10 to 1000 parts by weight ofthe following component (B), wherein the composition has a complexdynamic viscosity η*(1) at 250° C. of 1.5×10⁵ poise or less and aNewtonian viscosity index n of 0.67 or less: (A): a polyolefin-basedresin, and (B): a hydrogenated diene-based copolymer satisfying all ofthe following conditions {circle around (1)} to {circle around (7)},{circle around (1)}: the hydrogenated diene-based copolymer comprisesthe following structural units (a) and (b): (a): a vinyl aromaticcompound polymer block, (b): at least one kind of block selected fromthe following (b1), (b2) and (b3): (b1): a block obtained byhydrogenation of a random copolymer block composed of a vinyl aromaticcompound and a conjugated diene, (b2): a block obtained by hydrogenationof a block in the form of taper composed of a vinyl aromatic compoundand a conjugated diene in which the amount of the vinyl aromaticcompound increases gradually, (b3): a block obtained by hydrogenation ofa conjugated diene polymer block, {circle around (2)}: the total content(T: percentage) of vinyl aromatic compound units contained in thehydrogenated diene-based copolymer from 10 to 18% by weight, {circlearound (3)}: the ratio (S: percentage) of the content of the vinylaromatic compound unit of (a) in {circle around (1)} to the totalcontent of vinyl aromatic compound units contained in the hydrogenateddiene-based copolymer is 3% or more, {circle around (4)}: the ratio (V:percentage) of the number of hydrogenated conjugated diene units havinga side chain of two or more carbon atoms to the total number ofhydrogenated conjugated diene units in the hydrogenated diene-basedcopolymer is over 60%, {circle around (5)}: (T) in {circle around (2)},(S) in {circle around (3)} and (V) in {circle around (4)} in thehydrogenated diene-based copolymer satisfy the relation represented bythe following formula (1): V≦0.375×S+1.25×T+40  (1) {circle around (1)}:80% or more of double bonds in conjugated diene units in thehydrogenated diene-based copolymer are hydrogenated, and {circle around(7)}: the number-average molecular weight of the hydrogenateddiene-based copolymer is from 50000 to 400000.